Irises have long been among the most popular flowers for the home landscape. With their ease of growth and dependability, this perennial is sure to thrive year after year. Varying greatly from one species to another, iris plants offer their growers a wide range of forms, color, and growth habit from which to choose. Though most of these hardy plants are relatively carefree, gardeners will need to learn more about each type’s needs. Specifically, when they should be planted. So, when do you plant iris bulbs?

Can You Plant Iris Bulbs in the Spring?

Determining when the best time is to plant iris bulbs will depend greatly upon the type. There are over 100 species of iris, each differing somewhat in their garden needs. When to plant Dutch iris bulbs, for example, will differ from the timing of other types. Most of these flowers are grown by planting their rhizomes, roots, or bulbs. Though some irises can technically be planted in the spring, most prefer to be moved into the garden in either midsummer or fall.

A large majority of iris bulbs will benefit from fall planting. Iris species that should be planted in the fall are generally those which will begin to bloom in early spring or summer. Both tall and dwarf varieties of Dutch iris are best planted at this time. However, many growers have found success with very early spring plantings, as soon as the soil can be worked. Though the range of Dutch iris colors is somewhat limited, this species is especially popular in early spring mixed borders and in cut flower gardens. Another more common option, Siberian iris, can also be planted in this manner.

When to Plant Bearded Iris Bulbs

Various types of bearded iris afford growers magnificent diversity within flower beds. Though different cultivars may vary in bloom time, from spring through late summer, their planting process is generally the same. When considering larger species like bearded iris, when to plant will be of great importance to their establishment in the garden. Best practice dictates that bearded iris should be planted some time from midsummer to early fall.

Ideally, planting at this time helps to ensure that the iris is able to devote its energy to the development of a healthy root system before the arrival of winter. Bearded iris rhizomes which have been planted in early spring may bloom prematurely during the first summer. This causes the iris to bloom much sooner than a late planting, ultimately resulting in a weaker plant. Properly established iris plants will reward gardeners with beautiful iris blooms for many seasons to come.

Dividing Irises

After several seasons, bearded iris plants may become overcrowded and need to be divided. To do this, gardeners should wait until the plant has finished blooming and has died back naturally. At this time, the plant can be dug and divided. Replanting iris divisions in late summer or fall will help to ensure that new divisions are able to become established quickly before winter. For the best results, iris division should never be done in spring or during periods of active growth.

There are several hundred different species of iris. While not all types of iris are suited for use in the ornamental landscape, many specialized heirlooms and hybrids are ideal additions to cut flower gardens and in decorative flower beds. Though most irises are known for their distinctive true blue color, white iris varieties have gained popularity. Learning more about the different types of white iris can help you to choose the best candidate for planting in your own garden.

Types of White Iris 

1. “African” Iris - This type of white iris is unique for many reasons. Hardy to USDA growing zones 8-11, African irises are known for their grassy evergreen foliage and ability to produce multiple flowers throughout the season. Flower blooms are a crisp white color, with yellow and light purple markings. 
2. “Alba” - Iris cristata types of white iris are commonly dwarf. Alba is just one example of such a cultivar. Lush, green foliage thrives in shady garden spaces and will quickly multiply and naturalize where conditions are ideal. Their small size make ‘Alba’ white iris ideal for use in short flower borders or even as a ground cover plant. These bulbs, which are planted in the fall, will produce bright white flowers with narrow petals. 
3. “Gull’s Wing” - Gull’s Wing is just one of many popular white Siberian irises. When in peak bloom, flower stems reach heights of 3 ft. (.9 m.) Gull’s Wing is also one of the more showy white iris varieties, as each petal is large and wide. Additionally, white Siberian irises seldom have issues with disease or damage caused by insects. 
4. “Immortality” Bearded - White bearded irises are quite common in ornamental gardens. The cultivar Immortality produces large, pure white flowers. In addition to its large ruffled petals, this variety is also highly fragrant. Immortality will often rebloom in late summer. 
5. “Starring” Bearded - Starring is yet another of the white bearded irises. Unlike other white irises, this variety is accented by dynamic deep purple lower petals, called “falls.” Like many bearded irises, this low-maintenance plant thrives in full sun and looks great when used in mass plantings. 

Irises are a beautiful addition to flower beds and landscapes. Blooming in spring, perennial irises can range greatly in color and in fragrance. These unique characteristics make them popular with novice growers and plant collectors, alike. Though large iris plantings look stunning while in full bloom, if you’re a gardener without ample garden space you may be pleased to know that irises are also quite adaptable to container culture. 

Growing Iris in a Container

Though not traditionally considered to be a container plant, irises can grow well in a pot, provided it is large enough. Bigger pots are ideal, as many irises quickly establish robust root systems. Growing iris in a container will require special attention to the needs of the plant, specifically sunlight and watering. 

Irises should be situated in a location that receives full sun. Container iris plants also require a well-draining potting mix, as the plants can easily become waterlogged. This will help to reduce the likelihood of other common issues, such as root rot. 

How to Plant Potted Irises

Planting tall iris in a container is possible, however, making sure to properly secure or stake the plant. Most gardeners prefer to use dwarf iris in planters because they reach a much more manageable size. Regardless of type, special attention will need to be given during planting. Iris rhizomes grow best when they are situated at soil level, partially exposed. General spacing requirements may vary depending upon rhizome size, but most experts suggest around 6 inches (15 cm.) between each. After planting, water the containers well and continue frequent irrigation during the plant’s active growth until blooming ceases.

Be Sure to Deadhead

As iris blooms fade, deadhead the flowers by removing the stem down to the base of the plant. At this time, make certain to leave all of the other foliage intact. This will help to ensure the health and continued development of the rhizomes, in preparation for next season’s growth. 

Winter care for iris in containers varies depending upon your growing zone. However, most sources suggest the use of heavy mulching to protect potted specimens. 

With proper care, container iris plants are sure to return season after season. Since rhizomes will multiply each summer, plants may require division and repotting after several years.

Irises are spectacular flowers that bloom in late spring, after early spring bulbs like crocus, tulips, and daffodils. At least 200 different species have been identified around the world, but varieties and cultivars number in the thousands. Irises are versatile plants that range from miniatures topping out at 4 to 7 inches (10-18 cm.), or tall specimens reaching heights of 27 to 40 inches (69-100 cm.).

This tough plant, which grows from underground rhizomes, withstands difficult conditions and can survive in well-drained soil for many years, even when it's been forgotten and ignored. Iris is found primarily in arid, semi-desert areas but also in meadows, on grassy slopes and along bogs or riverbanks. 

What is the history of iris flowers and where did iris originate? Read on to learn more about this hardy, showy plant in which many of us grow in our gardens.

History of Iris Flowers

Iris flower history dates back to Ancient Greece and relevant drawings are still visible in a number of ancient palaces.

According to Greek mythology, Iris was the messenger of the gods, a connection between heaven and mortal human beings here on earth. Iris was the goddess of the rainbow and beautiful flowers sprouted wherever Iris stepped. 

Purple or dark blue iris have been a symbol of royalty in European countries throughout history. The beautiful iris flower, or fleur-de-lis, is the national flower of France. A reminder of the French revolution, fleur-de-lis holds a place of importance in the culture of New Orleans, Louisiana.

Certain types of iris flowers have been used medicinally for maladies such as coughs, colds, allergies, rheumatism, and cosmetically for dandruff, dry skin, and sweet-smelling perfume - sweet iris is a good example. 

The history of iris flowers in North America is thought to begin with early European settlers who brought the bulbs to the new world. Iris flower origins have been traced to Virginia, where bulbs were probably planted in the 1600's.

You are probably used to planting iris from rhizomes, but it’s also possible to grow the popular flowers from seed pods. Iris seed propagation takes a little longer, but it’s an effective, inexpensive way to get more iris flowers in your garden. If you are interested in picking and planting iris seeds, keep reading. We’ll give you tips on how to plant iris seeds in your garden.

Iris Seed Propagation

Can iris be grown from seed? Anyone accustomed to planting iris rhizomes may be surprised to hear that iris can be propagated from seed just as easily. It takes a little longer to get blooms, however, and they don’t necessarily look like the mother plant.

When you grow an iris (or any other plant) from its root structure, you are cloning the parent plant. This type of non-sexual propagation will produce an exact duplicate of the iris from which you cut a piece of rhizome.

With iris seed propagation, it takes two plants to make the new one. Pollen from one plant fertilizes a female flower from another. The resulting iris seed pods can produce plants with flowers that look like either parent or any combination of the two.

Harvesting Seeds from Iris

If you’ve decided that iris seed propagation is the way to go, you’ll need to start picking and planting iris seeds. The first step is harvesting seeds from iris plants.

Watch your garden plants as they bloom. If the flowers have been pollinated, they will produce seed pods. The pods start out small and green but expand quickly during summer months. When the pods are dry and brown, they split open, and the seeds are probably ripe.

Harvesting seeds from iris plants isn’t difficult, but the trick is not to lose the hard, brown seeds. Hold a paper bag under the stem, then snip off the iris seed pods one by one with a set of pruners like these Felco F5 Pruning Shears from Amazon, so that they drop into the bag. You can also gather any seeds that have fallen to the ground.

How to Plant Iris Seeds

Remove the seeds from your harvested seed pods and store them in a cool, dark place until you are ready to plant them. Picking and planting iris seeds can be done a few months apart, but it is also possible to store the seeds for years if you prefer.

Plant the seeds in autumn after the summer heat has cooled. In late October or early November, bring out the seeds. Select a bed with well-drained soil in full sun.

Cultivate the soil and remove all weeds in the bed where you will plant the irises. Press each seed about ¾ inch (2 cm.) deep and a few inches (8 cm.) apart. Mark the area well and watch for the baby irises to grow in spring.

Due to their wide adaptability, irises are a popular choice for many home gardeners. These plants range in size from dwarf to tall and come in a wide variety of lovely colors. Due to their perennial nature, irises can easily find their place in already established flower borders and landscapes or in new plantings. Though novice gardeners are able to grow these flowering plants quite easily, there are some issues that may cause a decline in iris plant health. Most commonly, iris borers can damage and even destroy iris plantings. With the addition of iris borer nematodes, however, this may not become an issue.

How are Nematodes Good for Iris?

One of the most common nuisance pests of iris flowers is the iris borer. In the fall, borer moths lay eggs on the soil near iris beds and on old plant matter in the garden. The following spring the eggs hatch and the larvae burrow into young leaves. As the borers feed, they gradually work towards the rhizome of the iris. Once in the rhizome, borers continue to cause damage until they mature.

This damage can cause severely stunted plants or even the total loss of iris rhizomes. In the past, iris borers have been extremely difficult to control through various chemical applications. Recently, the use of beneficial nematodes for iris borers has been brought into focus.

Microscopic nematodes for irises live in the soil. These entomopathogenic nematodes are able to find and feed on iris borers and their pupae, thus preventing damage to iris plants. However, when using nematodes for iris borers, timing will be most important.

Using Beneficial Iris Nematodes

After hatching early in the season, iris borers will be present in the soil as they search for young iris leaves in which to infect. This is the ideal time for nematodes to be released. Just as with any other product used in the garden, it will be vitally important to follow the manufacturer’s label carefully. If used incorrectly, the beneficial iris nematodes may have little to no impact on the borers.

In addition to applying iris borer nematodes in spring, many growers also choose to apply them in the fall. The use of a fall application can help to destroy any remaining adult larvae or pupae that are left in the soil. By doing so, you can greatly reduce the number of adult moths that occur in the garden the following growing season.

Iris fusarium rot is a nasty, soil-borne fungus that attacks many popular garden plants, and iris is no exception. Fusarium rot of iris is difficult to control and can live in the soil for many years. Read on to learn how to recognize iris basal rot along with tips for controlling this disease.

Recognizing Fusarium Rot of Iris

Iris basal fusarium is favored by warm, humid conditions. The disease generally attacks the roots first, and then enters the base of the bulb. It can also enter the bulb through cracks or wounds. Iris basal rot is spread by contaminated bulbs or soil, as well as splashing water, wind, insects, or garden tools.

The first signs of iris fusarium rot are generally stunted growth and yellowing leaves, often with lesions at the base. The disease may infect entire plants or symptoms may be limited to one side.

This disease destroys the roots before penetrating the base of the bulb. As a result, the plant is easily pulled from the soil.

The bulbs may look perfectly normal although the base may be shrunken and deformed, and the neck of the bulb may be softened. There may be a clear margin between healthy and diseased tissues. The husk usually turns pale or reddish brown, sometimes with a pinkish or white mass of spores. The rotted husk may remain firmly attached to the bulb.

Treating Iris Fusarium Rot

Purchase only healthy, disease free iris bulbs. Ensure the bulbs are planted in well-drained soil.

Avoid overcrowding, space plants apart so they have plenty of air circulation. Be careful not to wound the bulbs when digging or hoeing in the iris bed.

Apply a layer of mulch around the bulbs to keep the soil cool and prevent water from splashing on the leaves. Water bulbs carefully, preferably in the morning. Remove and destroy iris bulbs that show signs of damage or disease. Never plant bulbs that show a pinkish white fungus. Keep weeds under control as they often harbor disease pathogens.

Keep the plants as healthy as possible. Water regularly, but not too much. The same goes for fertilizer – feed iris plants regularly, but don’t overfertilize, especially with high nitrogen fertilizers, which may foster fusarium rot of iris.

Iris varieties are well loved for their striking blooms, range of colors, and ease of growing. These cheerful perennials aren’t too picky about conditions and reward gardeners with year after year of flowers. As with any plant, irises have their weaknesses, including the development of iris rust spots.

Know the signs of this disease and how to manage it to keep your plants healthy.

Identifying Iris Rust Disease

Iris rust is caused by Puccinia iridis, a fungal species. Most varieties of iris can be affected by this disease which causes a rusty, spot pattern on the leaves. Ultimately, the infection can kill leaves causing them to brown and die back but does not kill the whole plant. If you can control the disease, damage is typically minimal.

The main sign of this disease is spots that have a rust color on the plant’s leaves. The reddish brown lesions are rectangular in shape with a powdery texture. They may develop a yellow margin and they crop up on both sides of leaves. Eventually, if there are enough iris rust spots, a leaf will turn completely brown and die.

Preventing and Treating Iris Rust

Iris rust control begins with prevention. Conditions that favor the disease include humidity and moderately warm temperatures. Excessive nitrogen fertilization can also make irises more vulnerable to the infection.

The fungus can spread from one leaf and plant to another and also overwinter in plant material if temperatures remain mild. Removing and destroying any dead plant material in the fall is important for preventing the disease. It is also crucial in stopping the spread of the fungus if you have already identified it. Remove damaged leaves and dispose of them. Also, never plant irises in the same area where you have seen rust previously.

You may also want to take steps to treat rust on iris leaves if you have a severe infection. Fungicides can help control the disease. Try those that contain mancozeb, myclobutanil, or chlorothalonil. A local nursery or extension office can help you choose a fungicide and instruct you on the proper application process.

Looking to add some color to the early blooming crocuses and snowdrops? Try growing reticulated iris flowers. What is a reticulated iris? Read on to learn about reticulated iris care and related reticulated iris information.

What is a Reticulated Iris?

Reticulated iris (Iris reticulata) is one of 300 species or so of iris flowers. It is native to Turkey, the Caucasus, Northern Iraq, and Iran.

Reticulated iris flowers are small blooms of between 5 and 6 inches (13-15 cm.) in height. Each bloom has six upright petals called standards and three hanging petals, which are called falls. This iris is prized for its purple to blue, gold accented blossoms. Foliage is green and grass-like.

Additional Reticulated Iris Information

Named for the net-like pattern on the bulb’s surface, reticulated irises are a better harbinger of spring than crocuses. Unlike crocus, reticulated iris bulbs stay at the depth they were planted, thus giving a more realistic idea of the soil’s temperature.

The blooms are quite showy and make good cut flowers. They are said by some to be quite fragrant. Reticulated iris flowers are deer and drought tolerant and accept planting near black walnut trees.

Reticulated Iris Care

Reticulated iris flowers can be grown in USDA zones 5 to 9. They look their best when planted in masses either in rock gardens, as borders, and along walkways, streams, or ponds. They can be forced in containers as well.

Growing reticulated iris flowers is easy. They are tolerant of both full sun to partial shade in average well-draining soil. Plant the bulbs 3 to 4 inches (8-10 cm.) deep spaced 4 inches (10 cm.) apart in the fall.

Reticulated irises are propagated primarily through division. Bulbs tend to separate into bulblets or offsets after blooming. If flowering has declined, dig up the bulbs and remove (divide) the offsets post-bloom.

Reticulated irises are easy to grow plants that have few serious disease or insect problems, although fusarium basal rot is an infrequent occurrence.

Bearded iris is a popular perennial for its stunning flowers, variety of bloom colors, and striking, sword like leaves. Growing these flowers is not difficult, as they are drought tolerant. They only need to be divided every few years to maintain healthy, blooming plants. Replant your divisions in your garden or share with friends.

What is a Bearded Iris?

Bearded iris flowers are perennials that grow from rhizomes, modified underground stems that grow and spread horizontally in the soil. The flower of the iris has three petals that grow upright, known as standards, and three downward growing petals known as falls. The falls have a hairy texture, giving the flower the name ‘bearded.’

The name iris comes from the Greek name for the goddess of the rainbow, which indicates how much color variety there is in this perennial. There are hundreds of bearded iris varieties from which to choose that will give you not just different colors but also heights of leaves and flower stalks.

Different varieties of bearded iris can grow between 8 inches (20 cm.) tall for the miniature cultivars and up to just over 2 feet (61 cm.) for the tallest.

Bearded Iris Care

Bearded iris growing starts in late summer or early fall, the best time to put rhizomes in the ground for spring blooms. Plant the rhizomes horizontally with the top of each one just at the surface of the soil. It is important not to plant them too deeply.

Plant your irises in areas with soil that drains well and that gets at least six hours of sunlight per day. You can add organic material, like compost, or a balanced fertilizer when planting. Just avoid too much nitrogen, as this will limit flower growth.

Once your irises are established, you won’t need to water them unless you have an extended drought. Bearded irises are drought tolerant and waterlogged soil can be problematic.

To maintain irises, simply cut off the stalks after flowers have bloomed and remove any dead leaves. Cut leaves back in the fall. You will also need to divide and replant irises every few years to keep them healthy and blooming. Do this in the late summer by pulling the rhizomes up from the soil and removing newer rhizomes attached to at least a few leaves to replant elsewhere. Cut back the leaves by about two-thirds before you replant them or share with other gardeners.

Irises have long been a popular flowering plant, so popular that the kings of France selected them as their emblem, the fleur-de-lis.

Reichenbachii bearded iris plants are often overlooked, perhaps because of their diminutive size and subtle coloration, thus growing Reichenbachii iris is more often the province of the collector. Don’t discount these little gems; however. Iris reichenbachii info tells us that these iris plants have something special to offer. Let’s learn more about these species irises.

About Reichenbachii Iris Plants

Reichenbachii bearded iris is a member of the species irises and, along with the more popular hybrid dwarf and median irises, grows via rhizomes. Like its cousins, this bearded iris flourishes in sunny areas with well-draining soils.

It is native to Serbia, Macedonia, and into northeast Greece. These dwarf sized species irises bloom with one to two flowers at the top of the stalk. The little plants grow to about 4 to 12 inches (10-31 cm.) in height. The scant, albeit, quite large blooms can be seen in a variety of muted hues, from smoky violet to a blended yellow/brown.

Additional Iris Reichenbachii Info

As a garden specimen, Reichenbachii bearded iris may seem somewhat blah, but to a hybridizer, the makeup of this iris is pure magic. It turns out that Reichenbachii iris plants are quite unique in that they have chromosomes that are very similar to tall bearded irises and are compatible with them as well. Additionally, Reichenbachii bearded irises exist with both diploid (two chromosomes) and tetraploid (four sets) forms.

A hybridizer by the name of Paul Cook took one look at the fascinating genetics and thought he could cross breed Reichenbachii with the hybrid ‘Progenitor.’ Four generations later, ‘Whole Cloth’ arose, a hybridization sporting a new bicolor pattern.

Growing Reichenbachii Iris

Early summer bloomers, Reichenbachii bearded iris plants can be propagated via seed, rhizome, or bare root plants. They should be planted in full sun in rich, well-draining soil. Plant rhizomes in the early fall and bare root plants immediately.

If sowing seeds, sow to a depth equal to their size and cover with fine soil. Germination is most rapid when temperatures are 60 to 70 degrees F. (15-20 C.).

As with other bearded irises, Reichenbachii plants will spread throughout the years and should be lifted periodically to divide, separate, and replant.

If you think that iris plants are alike, the Algerian iris plant (Iris unguicularis) will definitely prove you wrong. Instead of blooming in summer, Algerian iris bulbs produce flowers in winter, when few other flowers are open. This lovely little flower is native to the hot regions of Tunisia, Turkey, and Greece. Read on for more Algerian iris information, including tips on how to grow an Algerian iris.

What is an Algerian Iris?

An Algerian iris is unlike any other iris plant in your garden in that it is winter blooming. The Algerian iris plant starts out slowly as it produces an evergreen mound of narrow, arching, grass-like foliage.

Then, starting in late fall, you will delight in its lovely flowers. Algerian iris bulbs produce small, lovely lilac blue flowers with a yellow throat. The flower stalks are not tall. Sometimes, they clear the foliage mound but sometimes blossoms appear beneath the foliage swords.

If you want to enjoy their lovely fragrance indoors, you can cut the stalk when the flower buds and watch it open up in a vase.

How to Grow an Algerian Iris

So, where can you grow Algerian iris bulbs? This type of iris is best suited to areas with mild winters. The Algerian iris grows well on the West Coast as well as in the Gulf states.

Generally, an Algerian iris does best in a hot garden area. Select a site that gets full sun. You might plant them near a wall to help maintain the soil’s heat and protect them from unexpected frosts. That said, these make great plants for a woodland garden in partial shade too.

Ideally, you should plant them in a location where you can appreciate the flowers in winter and early spring then ignore the plants the remainder of the year.

Bulbs of this plant grow happily in neutral or alkaline soil. They prefer dry soil and are drought tolerant, however, don’t neglect to give these iris plants an occasional drink. Once the blossoms are spent, cut the iris plants back.

Algerian iris plants do not like being disturbed so only divide them if it is absolutely necessary. Late summer is the best time to undertake this task.

Who can resist Dutch iris, with their tall, graceful stems and silky, elegant flowers? If you wait until late spring or early summer, you can enjoy them in the flower garden outdoors. However, those impatient for the rich colored blooms can also grow Dutch iris indoors by forcing.

Forcing Dutch iris bulbs is easy if you know the steps to take. Read on for information on Dutch iris forcing and tips on how to force Dutch iris bulbs to bloom in winter.

About Forced Dutch Iris Bulbs

While most irises grow from thick roots called rhizomes, Dutch irises grow from bulbs. This means that you can easily grow Dutch iris indoors by forcing them.

Dutch iris forcing doesn’t hurt the plants at all. The term “forcing” refers to a process of tricking the bulbs into thinking that bloom time has arrived well before the calendar announces spring. You manipulate the bloom time by giving the plants an artificial “winter” period, followed by sun and warmth.

Dutch iris forcing is a fun winter activity for everybody. Successfully forced Dutch iris bulbs brighten your house even when it is dreary outdoors. So how to force Dutch iris bulbs indoors?

How to Force Dutch Iris Bulbs

The process begins with a session in a cool location. Some winter-hardy bulbs, like paperwhite narcissus and amaryllis, can be forced to bloom indoors without a chill period. To grow Dutch iris indoors though, the bulbs need a cold period of 35 to 45 degrees F. (2-7 C.) that feels like winter.

The easiest way to accomplish this is to put the bulbs in a self-sealing plastic bag with slightly dampened peat moss for 8 to 12 weeks in the refrigerator or an unheated garage. This provides the required dormancy period for forced Dutch iris bulbs.

Once the dormancy period is over, it is time to provide the bulbs with the sun they need to bloom. To start forcing Dutch iris bulbs, place a few inches (8 cm.) of clean pebbles or florist marbles in a shallow bowl.

Set the flat end of the iris bulbs in the pebbles so that they remain upright. They can be placed quite close together, even as close as an inch (2.5 cm) apart. Add water to the bowl to a level just below the base of the bulbs.

Place the dish on a warm windowsill that gets indirect sun to allow the bulbs to sprout. When the forced Dutch iris bulbs develop shoots, place the dish in direct sun for bulbs to form. At this point, return the dish to indirect light and enjoy the bloom.

Known as the most adaptable, easy-to-grow iris plants, Siberian irises are finding their way into more and more gardens these days. With beautiful blooms in multiple colors, their dramatic but tough sword-like foliage, and excellent disease and pest resistance, there is no mystery why iris lovers are drawn to them. Siberian irises are known as a low to no maintenance plant, yet here at Gardening Know How, we are flooded with questions like “should you deadhead Siberian iris?” and “does Siberian iris need deadheading?” Click on this article for answers to those questions, as well as tips on removing Siberian iris flowers.

About Siberian Iris Deadheading

Siberian iris plants naturalize, forming clumps or colonies of 2 to 3 foot (61-91 cm.) tall plants in zones 3 through 9. Blooms form from spring to early summer on strong, erect stems above stiff, sword-like foliage. They bloom along with other spring perennials such as allium, peony, bearded iris, and foxglove. One of the notable characteristics is that their stems and foliage remain green and erect after the blooms fade. They do not brown, scorch, wither, or flop after blooming like other irises often do. Though the foliage will last a long time, Siberian irises only bloom once. Removing Siberian iris flowers once they've wilted will not cause the plants to rebloom. Wilted, spent blooms of Siberian iris can be removed to improve the tidy appearance, but deadheading spent flowers is purely cosmetic and has no actual effect on the health or vigor of the plants. Due to this, they can be paired with plants that flush out later, such as daylily, tall phlox, or salvia for successive blooms.

How to Deadhead a Siberian Iris

If you enjoy deadheading plants and prefer a pristine garden, deadheading Siberian iris blooms will not harm the plant either. For best plant appearance when removing spent Siberian iris blooms, cut the whole flower stalk back to the plant crown immediately after the flowers fade. Take care, however, not to cut back the foliage. This foliage photosynthesizes and collects nutrients throughout the growing season. In autumn, the leaves will begin to dry up, brown, and wither as all the stored nutrients move down into the root system. Foliage can be cut back to about 1 inch (2.5 cm.) at this point.

Louisiana iris has one of the most diverse range of colors of any iris plant. It is a wild plant that occurs in Louisiana, Florida, Arkansas, and Mississippi. As garden plants, these jewel-toned beauties thrive down to USDA zone 6. Healthy rhizomes are the key to growing Louisiana irises, as is moist soil. There are five separate species of this distinctive iris. Read on for some important Louisiana iris information, including growing, site, and care.

Louisiana Iris Information

The name "iris" is derived from the Greek word for rainbow, which is especially applicable with Louisiana iris plants. They come in a host of colors, primarily due to their ability to inbreed amongst the five separate species – Iris fulva, I. brevicaulis, I. nelsonii, I. hexagona, and I. giganticaerulea. In south Louisiana, all of these species occur amongst each other and freely hybridize naturally, resulting in colors not found in any other iris group. There are a few essential tips on growing Louisiana irises, which will result in healthy, beautiful plants in temperate to warm regions. This group of irises is also known as the Louisianans. In the wild they grow in ditches, bogs, roadsides, and any other moist or damp soils. As landscape plants, they thrive near ponds, in aquatic gardens, in containers, and any low area of the garden that retains moisture. The flowers come in rust, blue, purple, yellow, pink, and white as well as combinations of the core colors. Flowers occur on stems of 2 to 3 feet (61-91 cm.) in height. These brilliant flowers range from 3 to 7 inches (8-18 cm.) across and arrive in early spring, just as soil and ambient temperatures are beginning to warm. Leaves are attractive and sword-like. Mature clumps of Louisiana iris plants can span 3 feet wide (91 cm.). The foliage is persistent in warmer regions, adding architectural interest to the rain garden or consistently moist beds.

How to Grow a Louisiana Iris Plant

Irises grow from rhizomes, specially adapted underground stems. The Louisianans prefer a soil pH of 6.5 or lower and rich, moist soil. This variety of iris can also perform well in poor or even clay soil. Choose an area of the garden where the plants will receive at least six hours of sunlight and set out rhizomes in late summer or fall. In beds that tend to dry out, amend the area to a depth of 8 inches (20 cm.) with compost. Plant the rhizomes shallowly, with the top just barely visible above soil. Ensure the rhizomes stay moist or even boggy. Feed in early spring with compost tea or diluted fish fertilizer. In water gardens or at pond edges, it may be useful to try growing Louisiana iris in containers. Ensure they have wide drainage holes and situate the pot in the water.

Louisiana Iris Care

In regions that can expect sustained freezes, apply an organic mulch around the rhizomes. This can also prevent sunscald of rhizomes in hot summers. After spring blooms are spent, cut back the stalks, but allow the foliage to persist. One of the more important aspects of Louisiana iris care is water. These plants cannot be allowed to dry out and in raised beds, containers, or dry sites supplemental irrigation should be applied frequently enough that soil is consistently wet. Divide Louisiana iris in late summer. Division will revive old stands of the plant. Dig up the entire rhizome cluster and locate the rhizomes with green tips. These are the shoots that will grow the next season. Separate these from the old rhizomes. Replant the new rhizomes immediately, either in the bed or into containers.

Ever heard of water iris? No, this doesn’t mean “watering” an iris plant but pertains to where the iris grows – in naturally wet or aquatic-like conditions. Read on for more water iris information.

What is a Water Iris?

Although several iris types grow in wet soil, true water iris is a semi-aquatic or bog plant that grows best in shallow water deep enough to cover the crown year-round. However, most water iris plants will also grow in wet soil alongside a pond or stream, or even in a well-watered garden spot. True water irises include:

• Rabbit-ear iris
• Copper or red flag iris
• Siberian iris
• Louisiana iris
• Yellow flag iris
• Blue flag iris

Water Iris Growing Conditions

Planting a water iris in a wide pond plant basket or plastic pot to confine the growth is advisable, as some types of water iris, like yellow flag irises, can spread like crazy and may become difficult to control. Look for a location where the plant is exposed to the sun for most of the day unless you live in a hot, desert climate. In that case, a little afternoon shade is beneficial. If you don’t have a pond, try planting water iris in a whiskey barrel lined with plastic. The water should cover the crown by no more than 4 inches (10 cm.). Although water iris can be planted nearly every time of year in warm climates, autumn is the optimum time in other regions, as it allows time for the plant to get settled in before the arrival of cold weather. If the weather is hot, provide afternoon shade until the roots are established.

Water Iris Plant Care

Fertilize water iris plants regularly throughout the growing season using a general-purpose aquatic fertilizer to encourage the healthy growth of roots, foliage, and blooms. Alternatively, use a balanced, slow-release aquatic fertilizer. Water iris generally remain green all year in warmer climates, but any yellow or brown leaves should be removed to keep the plant healthy and the water clean. Cut water iris to just above the water line in autumn if you live in a cooler climate. Repot water iris into a slightly larger container every year or two.

Also known as zebra iris, sweet flag iris, and dalmatian iris, variegated sweet iris is a perennial in the bearded iris family with sweet, scented blooms. Sweet irises (Iris pallida 'Variegata') are often referred to as variegated iris or zebra iris plants because of their dramatic vertical stripping of gold, cream, white, and bluish green foliage. It gets its other common name of dalmatian iris because it is native to Europe, specifically the Southern Alps and Dalmatia. Continue reading to learn about sweet iris care and growing variegated sweet iris.

Growing a Variegated Sweet Iris Plant

The 2 to 3 foot (61-91 cm.) tall, sword-like, variegated foliage of sweet flag iris plants add interest to any garden style, even when the plant is not in bloom. Its lavender blue colored flowers bloom in late spring to early summer and its sweet fragrance attracts many pollinators. However, it is not just a beautiful ornamental plant. Orris root powder and orris oil are made from the rhizomes of zebra iris plants and are used in many herbal medicines and natural beauty products. Like most irises, sweet iris is seldom bothered by deer or rabbits and can be drought tolerant once established. Sweet iris is also more resistant to diseases and iris borers than other varieties. Still, it is wise to regularly inspect their rhizomes for borer damage.

Sweet Iris Care

Hardy in zones 4 to 9, sweet iris grows best in full sun to part shade locations with rich, moist but well-draining soil. Well-draining soil is essential, as wet feet can cause rot. Adding a little sand to the soil in the planting area can help it to drain properly. When planting irises, it is important to leave the tops of the rhizomes slightly sticking up from the soil level. Planting too deeply can also lead to rot and fungal diseases. While more shade tolerant than most other irises, sweet iris will bloom best in full sun. Zebra iris plants should be divided every two to four years to keep them healthy and blooming properly. Dividing should be done from late summer to autumn. When first planting or dividing iris plants, do not use a fertilizer that contains nitrogen. Otherwise, you should feed irises with a general-purpose fertilizer only three times a year-- in spring just as the foliage pops up, again right after its May through June blooming period, then again in fall to give the plant added stores of nutrients for the winter months.

Irises are beautiful spring flowers that add dramatic color and height to perennial beds. They’re also easy to grow in the right conditions, which include full or partial sun and moist soil with good drainage. The only issue with growing irises is that once the blooms fade, you’re left with shabby-looking foliage.

Don’t remove the foliage, as the plant needs it to store energy for next year. Instead, use thoughtful companion plants for irises to ensure additional summer flowers in the bed. You can use early spring flowers for the season’s first blooms, followed by irises, and then summer bloomers when considering what grows well with irises.

7 Best Iris Companion Plants

When selecting plants for this purpose, choose what plants grow well with irises. The companion plants for iris should thrive in the same conditions. Choose some that flower before irises and after, but also select flowers that will bloom alongside them and complement their colors. Here are some ideas of good companion plants for irises.

1. Daffodils (Narcissus spp.)

Daffodil bulbs, with their cheerful yellow blooms, provide characteristic early spring color. Like irises, they grow well in full or partial sun and slightly acidic soil that drains well. If you're unsure of your soil acidity then you can get it tested with something like this Rapitest Soil Test Kit for Gardens from Amazon that'll quickly analyze the soil pH. Plant bulbs in the fall, about two to four weeks before the ground freezes in USDA zones 3 through 9. Your chosen varieties of daffodils will bloom early, before irises, and possibly with a little overlap.

2. Allium (Allium spp.)

Allium species are ornamental onions with pretty, perfectly round flower clusters held on high, sturdy stems. They are striking in perennial beds and overlap with iris blooms. Growing alliums provides an interesting contrast of shapes when paired with irises. Plant allium bulbs in fall for late spring and early summer blooms. They like full sun and well-drained soil. You can grow allium in USDA zones 4 through 9.

3. Garden Phlox (Phlox paniculata)

Garden phlox is popular for its tall growth and long period of blooming from summer and well into fall. This is a great choice for lasting color after irises fade. Garden phlox grows from two to four feet (.60 to 1.2 m) tall. It grows best in full sun but will tolerate some shade. With garden phlox, you’ll have your choice of colors: purple, orange, red, magenta, and even bicolor types.

4. Black-Eyed Susan (Rudbeckia hirta)

Black-eyed Susan is a classic summer wildflower and native species in North America. It will bloom after the irises fade, making it a great iris companion plant. Like irises, it prefers moist soil that drains well and is best grown in full sun. Black-eyed Susan is suitable for gardens in USDA zones 3 through 8.

You can find Black-eyed Susan seeds readily available from Amazon.

5. Sedum (Sedum spp.)

Sedum is a large genus of plants, also known as stonecrop, including some North American native species. Sedum plants follow irises with disc-shaped clusters of small flowers that bloom through the summer and turn deeper shades in fall. They also offer interesting, fleshy foliage that complements the long spikes of iris plants. You can find low-growing species that act as groundcover and taller, upright types. Make sure the species you choose grows well in the same conditions as your irises.

6. Salvia (Salvia spp.)

Salvia plants are perennial flowers suitable for USDA zones 5 through 10. It is known for its pretty flower spikes that bloom in late spring, summer, and fall. You can get some overlap with irises as well as extended flowering. Salvia needs full sun and likes slightly acidic soil that drains well.

7. Annuals

Another great option for companion planting with irises is one or more annuals. Some annual flowers will bloom all summer long, from the time you plant them until the weather gets too cold in fall. Some examples of annuals that will grow in the same conditions as irises include petunias, cosmos, marigolds, and zinnias.

Frequently Asked Questions

Garden irises are hardy perennials and live a long time. They delight gardeners by blooming when the garden needs flowers, after the spring bulb blossoms have had their moment in the sun. Irises are easy-to-grow, graceful flowers that form the backbone of many a garden in this country, but they not entirely without problems. Iris root rot is one of them. Read on for information on root rot in iris and how to treat iris rot.

Root Rot in Iris

Root root in iris is also known as soft rot, and if your irises have ever had it, you know why. The leaves become soft, and the rhizome root grows mushy. Iris root rot is a caused by Erwinia carotovora, a bacterial phytopathogen. It usually gets inside the rhizome through an opening created by some kind of injury. Any pest could provide this entry, including borers, slugs, snails, beetle larvae or even rough use of tools. With iris root rot, you’ll first see yellowing at the center of the fan of leaves. In time, the center turns brown and collapses. Root rot in iris always produces a mushy, bad smelling rhizome. Often, you’ll also see decay in the plant’s leaves.

Preventing Rotting Iris Roots

Iris root rot is not easy to cure. However, many times you can avoid it by using good cultural practices in your garden. First, make sure that your irises are planted in sunny sites. Good soil drainage is critical, so consider raising your beds if need be to ensure proper drainage. Adequate spacing between rhizomes is also important since overcrowded plants are more vulnerable to bacterial growth. Don’t plant your rhizomes too deep in the soil, and keep dirt from the base of the fans. Never use fresh manure on your iris plants, especially if drainage is a problem. Instead, feed your plants with gentle fertilizers.

How to Treat Iris Rot

If you want to know how to treat root rot, it means your irises are already under attack. You’ll need to dig up each diseased rhizome and inspect it carefully. If the iris root rot is extensive, destroy the iris rhizome. Unfortunately, this is the only method of root rot control in iris if the rot has spread. You can learn how to treat root rot that is not so extensive, however. For less seriously affected plants, cut out and dispose of all parts of the rhizome that are diseased. Use sterilized tools to do this, and sterilize them again after use to prevent spreading the bacteria.

Irises are one of the easiest flowers to grow. They stem from rhizomes, which quickly multiply over the years, producing bigger, wider stands of these appealing blooms. When you notice iris plants not flowering, the cause can stem from a variety of issues including weather, soil fertility, overcrowding, unhealthy rhizomes, insect or disease attack, planting depth, and even site conditions. 

If you are wondering, "why are my irises not blooming," take a good look at these issues. Usually, we will find iris plants not flowering due to one of these easily corrected conditions.

Why are My Irises Not Blooming?

Bearded or Asian, classic or designer, irises are a pleasure to have in the garden. They provide a long term display of tall, glorious sword-like leaves and boldly featured blooms. Most irises have a wide hardiness range from USDA zone 4 to 9.

 When iris does not bloom, you still have beautiful foliage but the long waited for flowers refuse to appear. Frustrating as this is, it is generally something that can be fixed and flowers will appear the following year. 

There are many reasons for irises not blooming well, but what about why irises won't bloom at all? Most species of iris spring from rhizomes, although a few come from bulbs. Both these are underground storage structures that contain a reserve of carbohydrates and embryonic plants. 

When temperatures and lighting are right, they sprout stems and leaves and eventually produce flowers. Poor rhizomes or bulbs are often the cause of no flowers. If these are mushy, rotten, small, and under formed, then the result is stunted plants with few or no blooms.

Also, the plant needs well-drained soil in full sun for flowers to be produced. Irises in shady locations may fail to form blooms. Depth of planting can also cause iris plants not flowering. Rhizomes should be near the soil surface, ideally with the tops at or slightly below the soil surface.

Other Reasons for Why Irises Won't Bloom

If plants are correctly installed, have well-draining soil, and good light exposure, it may be a soil fertility problem. Conduct a soil test to see if the pH and fertility are consistent with good iris growth. Ideal iris soil pH is 6.8 and soil should have average levels of nitrogen, but sufficient amounts of phosphorus too, the nutrient that helps plants form flowers. 

An amendment of superphosphate, colloidal phosphate, or bone meal applied in early spring can help plants develop blooms. Another reason for iris plants not flowering is overcrowding. The rhizomes will increase over time and plants become too packed in their site. 

Dig up the clump and divide it, planting each rhizome individually in other areas of the garden. Retain just half the rhizomes in the existing area and water all transplanted rhizomes frequently. Over competition from other plants and weeds, which shade the iris bed, and insufficient water are other causes for why irises won't bloom. Irises are extremely drought tolerant but in the absence of any water, they will respond by refusing to bloom.

Another commonplace reason is a late freeze. Although irises tolerate freezing conditions well when not sprouted as long as the area is well draining, early leaves and stems can succumb to a freeze. When there are no leafy greens to draw in solar energy, flower production can screech to a halt.

Also, a freeze can kill any new buds that are just forming. Freezes experienced by plants six to eight weeks before bloom can simply abort the buds and prevent iris plants from blooming for a season. Insects and disease are seldom a problem, but if plant health is compromised, buds will rarely form.

There are many different types of irises, and differentiating iris flowers can be confusing. Some types are known by a variety of different names, and the iris world includes a number of hybrids too, which complicates things even further. Many people wonder how to tell the difference between flag iris and Siberian iris, two common types of iris plants. Read on to learn more about differentiating these flowers.

Flag Irises vs. Siberian Irises

So, what is the difference between flag iris and Siberian iris?

Flag iris plants

When people talk about “flag iris,” they are generally referring to wild iris. Flag iris includes blue flag (I. versicolor), commonly found in boggy areas and swamps of the northeastern United States, and yellow flag (I. pseudacorus), which is native to Europe but now found in temperate climates around the world. Both are types of beardless iris. Blue flag iris is ideal for wildflower gardens where the plant has access to plenty of moisture in spring. It makes a good pond or water garden plant, as it performs well in standing water. This plant, which reaches heights of 18 to 48 inches (46 cm. to 1 m.), displays long, narrow leaves, sometimes gracefully curved. The blooms are typically violet blue, but other colors also exist, including intense violet and white with bright pink veins. Yellow flag iris is a tall iris with stems that reach heights of 4 to 7 feet (1-2 m.) and upright foliage of about 5 feet (1.5 m.), depending on growing conditions. The ivory or pale to bright yellow blooms may be single or double, and some forms may display variegated foliage. Although yellow flag iris is a lovely bog plant, it should be planted carefully, as the plant tends to be invasive. The seeds, which float, spread readily in running water, and the plant may clog waterways and choke out native plants in riparian areas. The plant has done considerable damage to wetlands in the Pacific Northwest and is considered a highly noxious weed.

Siberian iris plants

Siberian iris is a hardy, long-lived type of beardless iris consisting of clumps of narrow, sword-like leaves and slender stems that reach heights up to 4 feet (1 m.). The graceful, grass-like leaves remain attractive long after the flowers have faded. Siberian iris types available in most garden centers are hybrids of I. orientalis and I. siberica, native to Asia and Europe. Although the plants grow well in wildflower gardens and along pond edges, they aren’t bog plants and they don’t grow in water. This is one sure way of differentiating between these and flag iris plants. Siberian iris blooms may be blue, lavender, yellow, or white.

Irises are old-fashioned garden plants with hardiness and persistence. They can delight for decades if divided and managed properly. There are many colors and several sports and cultivars of each species, allowing for a palette of tones. If an iris plant changes color, it could be a combination of things or simply a random accident. Here are some things to investigate that mysterious hue change.

Why Iris Flower Loses Color

Occasionally, we hear that an iris has changed color. There are several possible reasons why an iris flower loses color, but it generally doesn’t change color entirely. Temperature changes, chemical drift, transplant issues, or even random rhizomes dug up by a dog can cause a stand of iris to change color. Irises do not always bloom every year and an older variety may be asserting itself in your cultivar’s fallow period too. Several other explanations exist to account for color changing on iris. Loss of color, or fading, is common when the plant experiences extreme heat or cold. Additionally, the color can be influenced by lack of or excess light – for instance, when a tree has grown over to shade the bed. There is little evidence that soil pH or type will cause irises to fade. A deep, purple iris turns color when it matures and begins to die. Most of these options for an iris flower changing color change over time and the plant will resume its usual flower tones. Unexplained instances of an entire bed that was purple and turned white the following year will need to be delved into further.

Permanent Color Changing in Iris

When you find the entire iris plant changes color, the explanation is more complex. Irises grow from rhizomes that are just beneath the surface of the soil. In fact, old stands will have rhizomes growing right on top of the soil. These are easily broken away and can establish in any part of the garden they end up in. This happens when children play, during division or transplant, or even when the dog is digging in the yard. If a piece of rhizome ends up in another variety of iris, it can establish, taking over the bed and causing the iris flower to change color. More notable still, would be the presence of a sport. This is when the plant produces an offset that is not true to the parent. In these cases, the sport may bloom an entirely different shade.

Transplanting and Why Iris Turns Color

Another thing to think about is the strange issue of transplanting. You or someone else may have planted iris in the landscape years ago. Perhaps it didn’t bloom anymore because it needed division, or the site was not conducive to flowering. If any of the rhizomes are still alive and you transplant them into the location after amending the soil, the conditions are now optimum. Even a piece of the old rhizome can rise from the ashes and reestablish itself. If the older iris is a stronger cultivar, it may take over the new iris patch, making it appear the new iris plant changes color. The same thing can happen if you transplant your purple iris from a bed but inadvertently move others of a different color. Lo and behold, the next year you may have several different colors in the bed. The ease with which irises establish themselves makes them valuable, consistent performers. This same thing can cause some anxiety when they seem to come up with a different hue.

There’s no doubt that yellow flag iris is a gorgeous, eye catching plant. Unfortunately, the plant is as destructive as it is lovely. Yellow flag iris plants grow like wildfire along streams and rivers, and are commonly found in ponds, irrigation ditches and other riparian areas where they create all sorts of trouble. For starters, yellow flag iris plants threaten native wetland vegetation such as cattails, sedges and rushes. The plant also blocks water flow and damages bird nesting sites and important fish habitat. These hardy plants are found across the United States, with the exception of the Rocky Mountains. Learn more about its control in this article.

Yellow Flag Iris Control

When not in bloom, yellow flag iris looks much like familiar cattails, but the resemblance stops there. The plant, which spreads by long rhizomes and by seed, is easy to spot by its sword-like leaves and the bright yellow blooms that appear in late spring and early summer. Large clumps of yellow flag iris can measure 20 feet (6 m.) across. When you consider that new plants are easily generated by floating masses of seeds, it isn’t difficult to understand why controlling yellow flag iris is so challenging. Unfortunately, yellow flag iris plants are available in many nurseries, where the popular perennials are valued for their ornamental value and for their ability to effectively control erosion. As a result, many gardeners are unaware of the damage that results when the plant escapes.

How to Get Rid of Flag Iris

Be prepared for a long haul, as total control of yellow flag iris may take several years. Small patches of young plants are best controlled by pulling or digging – a relatively easy task in wet soil. You may need to use a shovel to dig out mature plants, along with a pickax to get the long taproots. Wear sturdy gloves and long sleeves because the resins in the plant can irritate the skin. Be vigilant about cleaning up debris because even tiny pieces of rhizomes can generate new plants. Don’t burn the plants because yellow flag iris re-sprouts quickly after burning. You can also control the plant by cutting stems and leaves below the waterline before the plant blooms and has an opportunity to go to seed. Don’t disturb the soil more than necessary; you’ll only create monster plants with stronger roots. Large infestations of yellow flag iris may require use of chemicals, usually in the form of products manufactured specifically for aquatic use. Consult a professional, as many states limit use of herbicides in aquatic environments. Note: Any recommendations pertaining to the use of chemicals are for informational purposes only. Chemical control should only be used as a last resort, as organic approaches are safer and more environmentally friendly.

German bearded iris (Iris germanica) is a popular, old fashioned flowering plant that you may remember from Grandma's garden. German iris planting and division is not hard, and German iris bulbs produce beautiful flowers that include draping petals called falls. Care of German irises is simple once they're settled into the right place in the garden.

Flowers of German Bearded Iris

The showy flowers have two parts, the upright part of the growing German iris is called a standard and the draping part is a fall, containing the beard. Many are multi-colored, but solid-color German iris plants are the oldest types. Foliage is upright and sword-like. When growing German iris, you'll find that most varieties are tall, good for a location at the back of the flower bed. Plants are available in both dwarf and intermediate heights for other areas of the garden. Stems that flowers grow on are sturdy and rarely need staking.

Tips for Growing German Iris

A few simple tips for German iris planting can get you started with growing this type of iris in the garden. These include:

• Plant German iris "bulbs," actually rhizomes, even with the soil. Planting too deeply encourages rot.
• Plant rhizomes in a loamy, well-draining soil.
• Growing German iris plants prefer a full sun location but will bloom in light shade.

Division of German Iris

Growing German iris is an easy way to add color to the spring and summer garden. Watering, fertilization with a high phosphorus fertilizer, and division every few years is necessary for the care of German irises. Division results in more prolific blooms and decreases the chance of soft rot and borer problems. Divide rhizomes of German iris every two to three years. If flowering has slowed on your German bearded iris, division may also be needed. When flowering has finished, lift German iris rhizomes from the soil with a garden fork. Replant the area, if desired, or leave some of the rhizomes in the ground. Plant extra rhizomes into other areas that will benefit from blooms of growing German iris.

When you are looking for an easy-care flower that loves wet conditions, then the Japanese iris (Iris ensata) is just what the doctor ordered. This flowering perennial is available in a range of colors, including purples, blues, and whites, with attractive medium green foliage. Care of Japanese iris is moderately simple when the plant is located properly. Learning when to plant Japanese irises is also an important part of their performance.

Growing Japanese Iris Plants

The timetable for when to plant Japanese irises may involve amending the soil with acidic, organic amendments prior to planting the rhizomes in early fall. Unlike many garden flowers, Japanese iris care does not involve planting in a well-draining soil. In fact, growing Japanese iris plants flourish in boggy areas, near ponds and water features or even potted and placed in these bodies of water. Water should be acidic. If you're unsure of the pH of your water, add 2 to 3 teaspoons (10-15 ml.) of vinegar to a gallon of water to obtain the level needed for successful care of Japanese iris. If a pond or water feature is not available, growing Japanese iris plants is best done in an area that remains damp and moist for best performance and easiest care of Japanese iris.

Care of Japanese Iris

Once planted and placed in the pond, Japanese iris care is minimal. Limit fertilization to plants with a well-developed root system, and only use plant food that is high in nitrogen. Japanese iris care will include the division of the rhizomes every three to four years. Crowded plants tend to offer fewer blooms. Division keeps growing Japanese iris plants in optimum condition to provide the best possible bloom in summer. After division, consider placing a few rhizomes in pots to live in your water feature or pond. Pot in a heavy soil, such as red clay mixed with sand. Growing Japanese iris plants are rarely bothered by disease or the borer which often attacks the traditional bearded iris. You can enjoy growing Japanese iris plants with delicate blooms in moist and shady locations if you provide plenty of acidic water. This simplifies their care and lets you just enjoy the flowers.

If you're looking for an interesting, moisture-loving plant to add to the garden, consider planting flag iris. Both growing conditions and flag iris care are relatively easy undertakings that will reward you with beautiful blooms each year.

What is a Flag Iris?

Flag irises are very hardy perennial plants that survive with minimal care and generally bloom in the spring and early summer. Flag irises are most often found in wet, low-lying areas and are suitable for similar conditions in the home garden. There are many varieties of flag irises, including dwarf and tall types. The most common types of flag iris plants familiar to most people include blue flag iris and yellow flag iris.

• Blue Flag Iris - Blue flag iris (Iris versicolor) is a beautiful semi-aquatic plant. Deep green foliage and striking blue-violet flowers appear on 2 to 3 foot (.6 to .9 m.)stalks in late spring to early summer. Leaves are narrow and sword-shaped. There are many species of blue flag iris and native plants are found along the edges of swamps, wet meadows, stream banks or in forested wetlands. This hardy plant adapts well to the home garden and is very easy to grow.
• Yellow Flag Iris - Yellow flag iris (Iris pseudacorus) is a perennial plant that is native to Europe, North Africa, Great Britain and the Mediterranean area. Yellow flag iris is prevalent all over North America, apart from the Rocky Mountains. Generally found along wetlands, streams, rivers or lakes in shallow mud or water, this hardy plant will also tolerate drier soil and high soil acidity. Gardeners often use this iris as an ornamental pond plant, and value the yellow flowers that bloom in the summer. However, it can quickly become invasive, and gardeners must beware of this in order to provide the most appropriate flag iris care.

Planting Flag Iris

The best place to plant blue flag or yellow flag iris is in a wet location that gets full to part sun. The plant can also be submerged in water for a time and still survive. Space plants 18 to 24 inches (45.7 to 61 cm.) apart.

Flag Iris Care

Flag irises do best in highly organic soil. Amend your garden area with compost or peat for best results. Provide a dusting of bone meal when you are planting flag iris. Be sure to water your plants liberally if the soil begins to dry out. Although flag irises are hardy and will tolerate spells of dry weather, they prefer to be moist. Provide a 2-inch (5 cm.) layer of mulch to protect plants and help retain moisture. Propagate plants by division right after flowering every two to three years to keep under control.

When growing Siberian iris (Iris sibirica), gardens will burst with early season color and intricate, frilly flowers. Planting Siberian iris en masse adds an elegant charm to the spring garden. Use these beautiful plants as a background border for other early spring bloomers.

How to Grow Siberian Iris

Learn how to grow Siberian iris for its lush, long-lasting blooms and low-maintenance, narrow foliage, which remains attractive after the blooms are spent. Easy Siberian iris care involves regular watering during the first year, limited fertilization and division of the clumps every three to five years. Through division and learning when to plant Siberian iris, you can ensure continuing blooms each year. Smaller and less common than the spring blooming bearded iris, Siberian iris offers a reliable perennial bloom for many years. Blooms of this flower have three petals on top, with three drooping petals below, known as falls. Siberian iris plants can reach as little as 12 inches (.3 m.) in height or grow taller than 3 feet (1 m.).

Planting Siberian Iris

You may wonder when to plant Siberian iris to enjoy the frilly blooms in your garden. The Siberian iris is adaptable to a range of planting times. To enjoy the blooms most readily, plant Siberian iris gardens from corms in late summer or autumn. If fall planting time has passed you by, and in more northern areas, planting Siberian iris in spring is perfectly fine; just don't expect blooms the same year. If you wish to add a few Siberian iris blooms to a container, you can plant them at any time. Planting Siberian iris gardens is best done in a rich, fertile soil with good drainage; however, Siberian iris will perform in lean or poor soils as well. The rhizomatous or fibrous roots can be planted in full sun to partially shady areas.

Siberian Iris Care

Keep the soil consistently moist until the plants are established, about a year. Water the established plants regularly when drought conditions exist. Feed Siberian iris plants in spring with a nitrogen-rich fertilizer and fertilize again when blooms are spent. This is the basis of Siberian iris care; they are rarely bothered by rots and borers as are the bearded iris. When planting Siberian iris flowers, consider the color scheme you desire for your garden and choose from the wide variety of colors available in pinks, whites, blues and purples. While many types are found in purple, here are some others you might find interesting:

• ‘Butter and Sugar' cultivar has white petals on top with yellow falls
• ‘Sultan's Ruby' offers deep magenta blooms
• ‘Wing on Wing' and ‘King of Kings' both have white blossoms

Numerous cultivars exist, so get creative with your color scheme when planning your Siberian iris gardens.

They're one of the first harbingers of spring and a personal favorite of mine—miniature irises. These beautiful wildflowers make great additions to woodland gardens and borders, offering a carpet of color each spring.

About Miniature Irises

It's still an iris, only smaller. In fact, most dwarf irises only reach about 6 to 8 inches (15-20.5 cm.) tall, making them ideal for borders or even edging. These tiny wildflower wonders spread through underground rhizomatous stems, filling the garden with their lovely spring blooms. While there are many types of dwarf iris, it's the dwarf crested iris (Iris cristata) that steals my heart. Dwarf crested iris will blanket the site with flowers that are rich in various shades of purple or bluish colors having white and yellow crested markings. There are many other cultivars as well, including white forms, so finding one that suits your needs shouldn't be hard.

Growing Crested Iris Plants

Growing and planting dwarf iris is not difficult at all. They prefer to be grown in areas that mimic their natural wooded habitat, which includes moist, well-draining soil. While it's not an absolute, dwarf-crested iris does appreciate some amending with sand and leaf mold. The plants should also be located in full sun or partial shade. However, if you're growing crested iris plants in full sun, then you'll need to ensure the soil doesn't dry out. Planting dwarf iris can be done in spring or fall. Shallow planting is preferable as with most other types of iris plants. Although these miniature irises are available from many reputable nurseries, if you're lucky enough to have the wildflowers growing on your property, they will transplant easily to a similar location in the garden.

How to Care for a Dwarf Iris

Once established in the garden, these little gems require hardly any care. In fact, they pretty much take care of themselves. Other than keeping the soil moist, which can be helped along by providing leaf mulch, you really don't need to do much else. As long as the soil is relatively fertile or amended with organic matter, there's no need for fertilizer either. You may, however, want to divide the plants every three to four years to reduce overcrowding. This is also a good way to propagate the plants. Simply divide the rhizomes in the fall once foliage turns yellow and replant elsewhere.

The iris borer is the larvae of the Macronoctua onusta moth. Iris borer damage destroys the rhizomes from which the lovely iris grows. The larvae hatch in April to May when iris leaves are just emerging. The larvae enter the leaves and tunnel into the plant causing structural and cosmetic damage as they go. In addition to this damage, the larvae introduce a bacteria that causes a soft, foul smelling rot. Iris borer symptoms may mimic those of common iris diseases.

Iris Borers Symptoms

Iris borers may be hard to see at first but they grow to 2 inches (2.5 cm.) long and are pinkish grubs. Iris borers symptoms are first noticed in April or May as they tunnel into the leaves. The leaves become ragged and dark streaked. The leaves will also leak a fluid. These symptoms also mimic bacterial soft rot, leaf spot, and iris scorch, all common iris diseases. Iris borer damage escalates to include mushy, foul-smelling rhizomes and stems and affects the entire vigor of the plant.

Iris Borer Damage

The most damaging aspect of the borer's activities is the affect on the iris rhizomes. They make holes in them and the tunneling and feeding opens the structures up to other bacteria and fungus. Irises are perennials which rise from their rhizomes every year. When the rhizomes are destroyed there are no storage structures to promote leaf and flower growth and the plant dies out. The bacteria the iris borer introduces will cause the rhizomes to rot from the inside out and produce a smelly fluid. The rhizome is destroyed and should be dug out to prevent the spread of the bacteria. Iris borer damage can effectively kill off an old established iris plot in one season.

Iris Borer Control

The moth responsible for these juvenile insects is rarely seen as it is a nocturnal creature. It lays eggs in fall which overwinter and hatch in spring. Iris borer control may start with planting strains that are resistant to the insects, such as Siberian iris. Good sanitation and a watchful eye can spot the signs of the borers and remove the leaves as they are moving in to the plant. Old leaves, flowers, and stems need to be removed in fall to remove the eggs that will overwinter and start the problem anew the following season. Killing iris borers requires a well timed insecticide application. Spinosad is a safe spray that is a bio-insecticide. It should be applied when the iris growth is just 6 to 8 inches (15-20 cm.) high in early spring. A repeat iris borer treatment in ten to fourteen days will help ensure that the pests have been eradicated. Another effective way of killing iris borers is with nematodes. Beneficial nematodes can be purchased in late winter or early spring in most garden centers. Nematodes are released during the rainy season. They are a safe and effective iris borer treatment which also works against many other garden pests.

The iris (Iris spp.) is a classic spring flower garden staple. With its lovely arching petals and tall, stately foliage, it is a bona fide showstopper in the landscape. Since there are several different varieties that come in a stunning array of colors and sizes that means there’s a perfect type of iris for almost every garden.

Their intricate and exquisite blooms thrive in sunny to partially shaded areas of the landscape and provide beauty starting in spring and into early summer, depending on the variety and your growing zone. Luckily for gardeners, iris care is often minimal once plants are established. That's art of why they're one of the most beloved types of flowers in the garden.

Though care needs vary depending on the variety, there are a few basic guidelines you should follow to grow the best irises in your flower garden. I’ll walk you through the fundamentals of how to plant and care for irises in the garden, as well as some of the most common varieties to choose from for a truly beautiful flowerbed full of irises.

Quick Iris Facts

Planting Irises

Late summer to early fall is the ideal time to plant spring-blooming perennials like irises. Before planting, soak iris rhizomes in water for a few hours. Plant rhizomes in a sunny location with rich, well-draining soil for optimum flowering. Leave about 12-18 inches (30-46 cm) between plants to allow for good airflow and to reduce pest and disease problems.

Irises, especially bearded irises, prefer shallow planting. Dig a hole that’s 6-8 inches (15-20 cm) deep and create a mound in the center of the hole to ensure the roots are underground, but the top of the rhizome is level with the ground. Leave the top of the iris rhizome partially aboveground or just beneath the soil.

Planting too deep is one of the most common reasons for irises not flowering. Bearded iris rhizomes need to be baked in the sun in order to bloom well, so don’t mulch after planting either.

For Siberian irises, plant rhizomes 1-2 inches (2.5-5 cm) beneath the surface of the soil in a moist but well-draining area. This type of iris is perfect for planting around ponds or streams or in shadier parts of the garden that hold onto more moisture. Water well after planting and continue to water regularly until established. After one to two years, irises are relatively drought-tolerant, but still benefit from irrigation during hot, dry spells.

Dutch irises are a bit different from the bearded varieties and Siberian types because they grow from bulbs rather than rhizomes. Plant Dutch irises in fall as you would other spring-flowering bulbs. But these bulbs require deeper planting than other iris varieties. Plant them 3-5 inches (8-12 cm) below the surface in a sunny area with light, well-draining soil.

Best Soil for Irises

Irises prefer moist but well-draining soil. Bearded irises prefer a neutral to slightly alkaline pH soil, but Siberian irises do best in a neutral to slightly acidic soil. A loamy or sandy soil is ideal for most irises, as clay soil can hold onto too much moisture and rot rhizomes or bulbs.

To improve your soil for irises, mix in homemade compost or organic worm castings, which you can find on Amazon, before planting. If you add compost to established plants, be sure not to bury the tops of the rhizomes as that can diminish flowering.

Iris Light Needs

Bearded irises need full sun to thrive, but they can tolerate some shade. For the best blooms, however, ensure you plant irises in a location that receives at least 6 or more hours of direct full sunlight per day.

Siberian irises and Japanese irises can tolerate more shade than bearded varieties. As long as they receive at least 4 or more hours of sunlight per day, they will thrive. But the more sun, the better the blooms.

How to Care for Irises

Caring for irises is pretty basic, but there are some guidelines gardeners should follow for the best blooms and long-lasting plants that will beautify your garden for years to come.

Watering Irises

Water irises thoroughly after planting or transplanting and continue to water regularly for the first growing season until plants are established.

Once established, irises – particularly bearded varieties – are drought-tolerant and are good plants for a xeriscape garden. But keep in mind, even drought-tolerant plants benefit from occasional watering. Provide additional water during hot, dry periods or when you see foliage wilt.

Siberian irises are water-lovers, so they require more frequent irrigation than their bearded cousins. Ideally, plant them in a location near water, like a wildlife pond or natural stream. They are also well-suited to rain gardens.

Siberian irises, despite their love for moist soil, are still relatively drought-tolerant once established. But it’s best to provide them with some form of irrigation during the summer. My irises thrive when I water them with this drip irrigation system you can get at the Home Depot. It provides consistent, directed moisture right at the roots where plants need it.

Best Fertilizer for Irises

Bearded irises require less fertilizer than their beardless counterparts. Be careful not to let fertilizer touch the rhizomes when feeding irises. It’s best to add a low nitrogen fertilizer, like this one from Amazon, to your garden bed or planting holes when you are first planting new irises or transplants. Higher levels of phosphorus and potassium will help your irises produce more blooms.

But be careful not to overfeed your irises. You can reapply fertilizer in the spring before blooms appear or side-dress plants with compost. Irises don’t need that much fertilizer, though, to thrive.

They are generally low-maintenance and will continue to bloom abundantly as long as you site them well, don’t plant them too deep, and divide plants when they start to look bare in the center or when blooms diminish.

Mulching Irises

Bearded iris rhizomes need to be close to the surface of the soil to bloom well and thrive, so don’t mulch over top of rhizomes or else risk losing blooms. If you want to mulch to suppress weeds around bearded irises, just make sure the pull back mulch from the top of the rhizome.

Siberian and Japanese irises are moisture-lovers, so they benefit from a light layer of organic mulch, like this one from Amazon, to help keep soil moist. But root rot can still be an issue for these varieties, so don’t pile mulch too high or else you can cause issues.

Pruning Irises

There are two main ways to prune irises: deadheading and cutting back for winter. Neither is necessary for irises to grow or bloom, but proper pruning can help plants thrive and bloom more.

Deadheading Spent Blooms

Deadheading Siberian irises and bearded irises is not necessary. The seedpods can add unique beauty and interest to the garden in the late summer and autumn.

However, leaving seedpods may direct energy away from the plant roots. To get bigger blooms next year, deadheading is a good idea. This allows irises to send all their energy back into the roots and rhizome instead of expending it on producing seeds.

Preparing Foliage for Winter

The tall, strappy leaves of the iris look beautiful and can add a lovely architectural element to the garden even after blooms fade. And as with many spring blooms, the foliage sends nutrients to the rhizome for next year's flowers. So while many gardeners wish to immediately remove foliage once flowering is done, resist the urge because the leaves are helping build up next year’s blooms.

Enjoy the foliage in the summer and then cut back leaves after the first frost or once they yellow in fall. Leave at least 1-2 inches (2.5-5 cm) of foliage when you prune irises. You can also leave foliage alone for winter and cut back dead leaves in spring when new growth begins to emerge.

Iris Care Calendar

Types of Irises

There are a wide range of different types of irises that originate from all over the world. Let's take a look at broad categories of irises as well as some of the specific varieties.

Bearded Irises

The most common type of iris in the United States is the bearded iris, sometimes called the German bearded iris (Iris germanica). These beautiful spring bloomers are native to central and southern Europe. There are reblooming cultivars that put out a second show of flowers in summer, fall, or winter.

The height of the bearded iris plant ranges from 3 inches (7.6 cm) for the shortest dwarf iris flowers to 4 feet (1.2 m) for the tallest of the tall bearded iris. There are several classifications of bearded irises, divided by size. Here are the different types of bearded irises by height, from shortest to tallest:

• Miniature Dwarf Bearded (MDB) are the smallest type of bearded iris. They grow up to 8 inches (20 cm) tall.
• Standard Dwarf Bearded (SDB) are a little bit larger. They can grow up to 8-16 inches (20-41 cm) tall.
• Intermediate Bearded (IB) reach heights of 16-28 inches (41-71 cm), making them a nice size for garden borders.
• Border Bearded (BB) irises are the same size as intermediate bearded irises, but come in a variety of attractive ruffled flower forms.
• Miniature Tall Bearded (MTB) irises are taller but daintier than other large varieties. They grow between 16-28 inches (41-71 cm) high and have delicate blooms that float atop slender stems, making them perfect for spring bouquets and arrangements.
• Tall Bearded (TB) irises are the largest bearded variety. They grow 28 inches (71 cm) high and above.

Beardless Irises

Beardless iris flowers bloom in shades of purple, blue, white, and yellow and include many hybridized versions that are multi-colored. There are a several different types of beardless irises, including some that are native to North America. Here are some of the most common types:

• Siberian Iris (Iris sibirica): Known for their slender foliage and cold hardiness, Siberian irises are more dainty than bearded varieties. They come in a plethora of colors, but the traditional type is a rich purple with yellow and white markings. For a pop of spring color, try the ‘Butter and Sugar' cultivar, which has soft yellow and white flowers.
• Japanese Iris (Iris ensata): Japanese irises have beautiful, butterfly-like blooms that are flatter than other iris varieties. They come in a wide range of colors and prefer moist, acidic soils and partial shade. Japanese irises bloom later than bearded varieties, so they’re a great addition to the midsummer garden.
• Dutch Iris (Iris x hollandica): Dutch irises are not like other iris varieties because they grow from bulbs rather than rhizomes. You plant iris bulbs in the fall like other spring-blooming bulbs, such as tulips and daffodils. Then in the spring, they put out lovely, delicate blooms that are perfect for cut flower arrangements.
• Louisiana Iris: Louisiana irises are a group of irises that are native to the southern United States. They come in a huge assortment of colors and make great additions to native plant gardens in that part of the country. For a truly stunning iris variety, try the ‘Black Gamecock' iris. It’s such a deep purple it almost appears black.
• Spuria Iris (Iris spuria): The Spuria iris, planted along with the Siberian iris, offers blooms later in the spring once the bearded iris is finished blooming. Many of the flowers on spuria irises are ruffled and include a draping set of three outer sepals called falls.

Aril Irises

There are two different types of aril irises that are native to the Near East. They are Oncocyclus irises and Regelia irises. They are both bearded, but the beard is not as prominent as it is on the bearded iris. There are also arilbred irises (AB), which are hybrids of aril irises crossed with bearded irises.

Aril irises come in a wide array of colors and they have large, impressive blooms. However, these irises are extremely difficult to grow in most parts of the United States, unless you live in a very hot and dry location similar to their native Near East climate.

Shop a huge array of amazing, high-quality irises from Wayside Gardens.

Propagating Irises

The primary method of propagating irises is division. Dividing plants regularly every few years is part of proper iris care as well as a great way to expand your collection of plants.

How to Divide and Transplant Irises

Good iris care includes dividing plants every 3 to 5 years to ensure continued blooms. Iris plants are abundant multipliers, but once the rhizomes become crowded, flowers may diminish.

A clear sign it’s time to divide your iris is when it develops a hole in the center of the plant. Overgrown irises stop producing leaves and flowers in the center of the plant and only grow around the edges of the clump.

When this happens, first cut back foliage to about 6 inches (15 cm). Late summer to early fall is the best time to divide irises. Wait until the heat of summer has passed, but before freezing overnight temperatures begin.

Use a clean, sharp shovel to dig up the entire iris and inspect it for any pests or diseases. Remove any infected or infested parts of your iris then divide the healthy parts of the plant into smaller sections. Make sure to include an entire rhizome in each newly divided iris clump. Replant the divisions the same way you would plant a new iris. Water thoroughly.

Iris Problems

Irises are generally free of problems and easy to grow, but there are a few issues gardeners should know about. The most common and worst iris pest is the iris borer. The adult moths lay eggs on iris foliage in late summer. The larvae hatch and travel down the leaves and into the rhizomes in spring, where they begin to feed.

Foliage affected by iris borers will turn yellow and flowerbuds will become brown and watery. Borers can cause the rhizome to rot and die. To prevent this pest, clean up foliage in late winter or early spring before temperatures are consistently above freezing to get rid of any overwintering borer larvae. Eggs begin to hatch around 72ºF (22ºC).

Beneficial nematodes, which you can buy on Amazon, also attack larvae in the spring and can help protect irises from infestations.

The most common disease that impacts irises is bacterial soft rot. Iris borers make plants more susceptible to soft rot. The bacteria enters the plant’s rhizomes via cracks, cuts, and wounds from borers.

The rhizome becomes mushy and smells rotten. To control bacterial soft rot, dig up the affected iris and remove any diseased parts. Replant the healthy sections or throw out the entire plant if it is entirely infected.

There are many reasons why people need to learn how to store iris rhizomes. Perhaps you got a great deal on irises late in the season, or maybe you received a few from your friend who had divided their irises. Whatever your reason for storing iris rhizomes, you'll be happy to know that it is easy to do.

How to Store Iris Rhizomes

Before we look at how to keep iris over the winter, we need to make sure that it is understood that we are talking about storing iris rhizomes in this article. Irises that grow from rhizomes typically have flat, sword-shaped leaves. Proper iris rhizomes storage starts with making sure that the iris rhizomes have been properly dried. After digging them up, trim the leaves back to about 3 to 4 inches (7.5 to 10 cm.) long. Also, do not wash the dirt off. Instead, allow the iris rhizomes to sit in the sun for a day or two until the iris rhizomes are dry to the touch. Using a scrub brush, gently brush off most of the dirt. There will be some dirt left on the rhizome. The next step in preparing iris rhizomes for storage is to place them in a dark, dry, somewhat cool place to further dry or cure. They should have plenty of air ventilation and it should be about 70 F. (21 C.). Leave the iris rhizomes there for one to two weeks. After the iris rhizomes have cured, coat them in powdered sulfur or other anti-fungal powder. This will help prevent rot from setting in on the rhizomes. The last step in storing iris rhizomes is to wrap each rhizome in a piece of newspaper and place in a box. Put the box in a cool, dry place. Every few weeks, check on the iris rhizomes to make sure that rot has not set in. If the iris rhizomes start to rot, they will feel soft and mushy instead of firm. If any do start to rot, discard the rotting iris rhizomes so that the fungus does not transfer to any other rhizomes in the box.

Iris leaf spot is the most common disease affecting iris plants. Controlling this iris leaf disease involves specific cultural management practices that reduce the production and spread of spores. Wet, humid-like conditions make the ideal environment for fungal leaf spot. Iris plants and the surrounding area can be treated, however, to make conditions less favorable for the fungus.

Iris Leaf Disease

One of the most common diseases affecting irises is fungal leaf spot. Iris leaves develop small brown spots. These spots can enlarge quite quickly, turning gray and developing reddish brown edges. Eventually, the leaves will die. Moist, humid conditions are favorable for this fungal infection. Leaf spotting is most common during wet conditions, as rain or water splashed on the leaves can spread the spores. While infection of iris leaf spot generally targets the leaves, it will occasionally affect the stems and buds as well. If left untreated, the weakened plants and underground rhizomes may die.

Treatment for Iris Plant Fungal Leaf Spot

Since the fungus can overwinter in infected plant material, removing and destroying all diseased foliage in the fall is recommended. This should significantly reduce the number of surviving spores come spring. Fungicide application may also help following the removal of infected plant material. Severe infections may require at least four to six fungicide spray treatments. They can be applied in spring to new plants once they reach about 6 inches (15 cm.) high, repeating every seven to ten days. Adding ¼ teaspoon (1 ml.) of dishwashing liquid per gallon (4 L.) of spray should help the fungicide stick to the iris leaves. Also, keep in mind that contact fungicides easily wash off in rain. Systemic types, however, should remain active for at least a week or two before reapplying.

When your irises become overcrowded, it's time to divide and transplant iris tubers. Generally, iris plants are divided every three to five years. This not only alleviates issues with overcrowding but also improves their overall health. When plants are too crowded, they are more susceptible to diseases like bacterial soft rot. In addition, plants are less likely to produce any blooms. Keep reading to learn more about replanting bearded irises.

When & How to Divide Bearded Irises

The best time to divide irises is during late summer, usually anytime between July and the first of September. Carefully dig up your iris clumps with a spade shovel and gently lift each clump from the soil. Shake off the soil and rinse each rhizome with water. Trim the existing foliage into a neat fan about a third of their overall height, then use a sharp knife to cut or separate the rhizomes. In some cases, you may be able to just pull them apart. Make sure that each division or section contains a fan of leaves. As you divide the rhizomes, take time to inspect them. Discard any that are old, leafless, soft, or rotting. Soft rot and iris borer are two of the most common causes for soft, mushy rhizomes in bearded irises. Replanting only the younger, healthier rhizomes will ensure the continual growth and vigor of your bearded iris plants.

Bearded Iris Transplant Instructions

Once you've ensured the health of your rhizomes through thorough inspection, you're ready to transplant iris tubers. However, prior to transplanting irises, you'll need to locate a similar area for replanting. Bearded iris plants perform best in fertile, well-draining soil in areas with full sun. Their blooming is poor when given too much shade and poor draining can lead to bacterial soft rot. Dig a hole large enough to accommodate at least three to five rhizomes. Mound the center with soil and place the rhizomes (with fans facing in one direction) on top, allowing the roots to sprawl over. Then fill in the hole and cover the rhizomes slightly—no more than an inch (2.5 cm.) or just below the soil surface. Planting too deep can also encourage rotting. Replant additional rhizomes the same way, spacing each group at least 12 to 24 inches (31-61 cm.) apart. Water the irises thoroughly after transplanting. Newly planted irises should begin flowering within their second or third season.

With over 100 varieties of irises, there are many colors, petal shapes, and levels of showiness you can choose from. After finally deciding and planting your iris, you may find that you put your plant in the wrong spot. Or, you may need to divide your iris and transplant the babies elsewhere. Transplanting an iris is a routine part of its care, but many gardeners don't know when or how to move it to a different space. Keep reading to learn the answers to these questions and more!

Bearded vs. Siberian

First, you should determine whether you have a bearded or a Siberian iris. Both bearded and Siberian irises are excellent additions to the home landscape, but each have different needs. While bearded irises are best known for their large, colorful blooms, Siberian iris types have long been praised for their ease of growth and ability to multiply quickly. Large beds of these species will continue to bloom, even after becoming crowded. Bearded iris will generally require division on a much more frequent basis to keep the plants looking their best.

Signs You Need to Divide an Iris

Learning when to transplant irises will vary depending on the type, but most will show many of the same signs when it is time for division. Large groups of plants will produce impressive mounds of foliage. Though these leaves can be quite beautiful, beds that have become too crowded may see a decline in overall health. For example, the rhizomes may start heaving out of the ground. Overcrowded iris rhizomes will push on each other, which results in the entire root system literally pushing themselves out of the ground.

Decreased flowering will also be a key signal that plants may need to be lifted from beds. If you check the roots, they may look like a mass of snakes or a pile of spaghetti, which is a sign that they must be divided.

When to Divide & Transplant Irises

Determining when to divide irises can be difficult for beginner growers. Digging out the plants in spring or fall may be tempting, but doing so may interrupt their natural growth cycle. It's best to wait until the flowers have finished blooming, which makes mid-late summer the ideal time to divide clumps. Learning more about this process and about transplanting irises back into the garden will be essential in helping perennial beds to thrive season after season.

How to Divide Irises

1. Dig - Irises multiply through the production of underground rhizomes. Each of these structures must be removed from the ground and separated to divide the plants. This can be done with the use of a garden spade or fork. We recommend this Fiskars 3-in-1 Garden Tool Set, which includes a spade, from Amazon.
   Working in a circular motion around the perimeter of each plant, start by lifting the clump of iris plants out of the ground. If possible, lift the whole mass out whole, but if you can't do this, carefully break the clump into smaller parts and lift these out. Excess dirt should then be knocked free or rinsed from the plant, giving a clear view of the root mass.
2. Divide - Dividing irises begins next. While some rhizomes can be easily separated by hand, others may require a clean, sharp garden blade or bypass pruners to cut each apart carefully. These Fiskars bypass pruners from Amazon are a great choice. Each iris rhizome should be divided into pieces that are 3 to 4 inches (8 to 10 cm) long and consist of a few essential parts: at least two blades of healthy foliage and a small segment of root ball.
3. Discard Unhealthy Rhizomes - Though uncommon, you may encounter rhizomes that look weak or show noticeable signs of disease. Healthy rhizomes should be firm, not soft, and lacking noticeable cuts, spots, etc. Unhealthy rhizomes include those that have rotted, decayed, or been damaged by insects. These rhizomes should be removed from the garden and disposed of immediately.
   Diseased rhizomes should never be added to the compost pile. This will help to prevent the recurrence and spread of disease within iris beds. If you have any sections of rhizome that have no leaf fans. These can be discarded as well.
4. Trim Foliage - You should trim back plant foliage before or after division. This can be done by clipping each leaf back to approximately one-third of its height. Trimming back leaves at this time will help keep new plants healthy and aid in their preparation for the winter season.

How to Transplant an Iris

1. Choose a Location - Iris transplants will grow best in full-sun flower beds, receiving at least 6 to 8 hours of light daily. Adequate sunlight will be vital to the production of flower buds. While irises grown in exceptionally warm climates will benefit from afternoon shade, too much shade may negatively impact their growth, resulting in decreased or complete loss of flowers.
2. Prepare the Rhizomes and Soil - Once the iris rhizomes have been divided, you can replant them. First, trim the leaf fans back to about 6 to 9 inches tall (15 to 23 cm). This will allow the plant to re-establish its roots without having to support a large amount of foliage.
   Irises require well-amended growing beds with high soil fertility. The addition of compost and other organic matter is common. You can use a soil test kit, like this one from Amazon, to determine what amendments you need for your soil. Particular emphasis should also be placed on drainage, as irises cannot tolerate waterlogged soils or drain poorly. These plants are quite adaptable to growing in raised beds, containers, and pots.
3. Don't Plant Too Deep - At planting, special attention should be given to depth. Rhizomes planted too deeply may struggle to establish themselves within new beds, resulting in decreased production of flowers. Make sure to position your plants so that the top of each rhizome sits just below or at the soil level.
   If planting several irises near each other, point the rhizomes away from each other and space them 18 inches (46 cm) apart. Spread the roots out around the rhizome and then cover the roots and the rhizome with dirt.

Post-Transplant Iris Care

Once situated in the garden, new iris plants require little care. Watering beds deeply after planting promotes growth and the production of new roots. Establishing a robust, healthy root system will be essential for each plant’s winter preparation. Use a drip irrigation system like this option from Amazon to ensure consistent watering at the roots. Though your irises may start making new leaves after being transplanted, they should still be trimmed back in autumn.

When learning how to grow iris plants like Dutch, English, and Spanish irises successfully in the garden, correct iris bulb planting is important.

When and How to Grow Iris

You should plan on planting iris bulbs like these early in the fall. These small bulbs have a rough tunic on the outside. The bottom is the part that has the flattened basal plate, so obviously the top is the opposite end.

Group Planting Iris Bulbs

In groups of five to ten bulbs in a nice flower border, plant Dutch, English, and Spanish irises. Each group of bulbs should be planted next to perennials such as peonies. This arrangement helps hide their foliage when it withers away.

Iris Bulb Planting

Follow these steps for growing Dutch, English, and Spanish irises in the garden:

• Choose a site that has reasonably fertile soil and plenty of moisture. In other words, you want soil that won't dry out in summer. Dutch and Spanish irises have a habit of producing leaves in autumn and winter, so they need a sheltered environment. Good drainage will help them survive the winter.
• You should buy the bulbs early and plant them as soon as you can in deep soil, with about 5 to 7 inches (13-18 cm.) of soil over the top of the bulbs. Dutch irises are an exception to the early-planting advice.
• Dutch and Spanish irises are best lifted and stored out of the ground over the summer. This means you need to dig them up and store them in a cool, dry place. Lifting them provides the dry resting and ripening period they need for a great flowering season the following year. Don't sun-dry them; storing them in a well-ventilated place is perfectly fine.
• Then, simply replant them in late fall.

Now that you know the basics for how to grow Dutch, English, and Spanish irises, you can get started on your iris bulb planting for enjoyment each season.

Rock garden irises are adorable and delicate, and adding them to your rock garden can add charm and delight. Learn more about planting rock garden irises and their care in this article.

How to Plant Rock Garden Iris

For planting rock garden irises, follow these guidelines:

1. Plant the bulbs in groups of ten or more, and about an inch (2.5 cm.) or so apart. If you plant them singularly, they are easily overlooked.
2. Be sure to set the bulbs relatively deep, with 3 or 4 inches (8-10 cm.) of soil over the top. If your soil is free-draining and water doesn't puddle and moves freely through the soil, more soil is okay.

One problem with the little rock garden iris is that during the first year of planting, it flowers just fine. After that, for some reason the plant just sends up leaves and each original bulb splits into tiny rice-grained-sized bulbs. These tiny bulbs don't have the food reserves to help support the production of flowers. Deeper planting helps, and so does extra nourishment. You can apply liquid fertilizer in very early spring while the leaves are actively growing, or you can work around this issue by just planting new bulbs each spring. These bulbs are inexpensive enough that this solution isn't that bad.

Forcing Rock Garden Iris

Rock garden irises are a very easy to force. Just plant some of them in the fall at the same time as you plant other bulbs outside. Follow these steps:

1. Buy a bulb pan or an azalea pot. Bulb pans are half as high as they are wide, and azalea pots are two-thirds as high as they are wide. They both have the most pleasing proportions for these little irises because a standard pot looks kind of massive.
2. Whatever pot you choose, make sure that the pot has a drainage hole. You will want to cover the hole with a piece of window screening or pot shard to keep soil from falling out.
3. Fill the pot with rock garden iris bulbs almost touching in the right soil. Cover the bulbs with about an inch (2.5 cm.) of soil.
4. Water moderately right after planting to ensure they get enough moisture.
5. Provide about 15 weeks of a chilling period to help the bulbs form roots; then bring the pot into warmth and light for to help them flower.