5 Overgrown Perennials To Divide In August For Free Plants Next Year and a Tidy Garden This Fall
August gardens can look a little overgrown, but you can go ahead and divide these perennials now for an explosion of plants next spring.
August is still summer, but it’s the end of summer, and perennial plants have been growing for many months since early spring. That means that many of these plants are overgrown by summer’s end and would benefit from being divided.
Division is a type of perennial propagation in which you dig up the root clump and chop it up to create several plants, then replant each section. August is an ideal month to divide plants since cool nights and warm soil will encourage roots to regrow quickly.
Which plants to focus on? Give preference to species that have finished flowering and are showing crowded centers. Summer’s end is a fine moment for dividing plants - from geraniums to shade-loving hostas. It makes your borders neater and gives you healthier, happier plants next year. Grab a perennial shovel from Lowe's that is specifically designed for dividing and transplanting perennials to make the task easy as pie. Here are half a dozen perennials that will benefit from being divided now.
1. Bearded Iris
With six petals – three upright, three drooping - the bearded iris (Iris germanica) is an extremely popular perennial. It is beloved for its huge, showy blossoms that are super-fragrant and have a frilly beard in the center. It’s this beard with pollen and nectar that attracts pollinators. The plant also sports long, strappy, sword-like leaves. It’s a powerhouse in the garden and can grow to a mature height of some 4 feet (1.5m).
Bearded iris is hardy to USDA hardiness zones 3-9. It needs well-draining soil to thrive, sandy is preferred, and full sun exposure. Water when the top few inches of soil are dry. Never let that soil get wet – and never mulch this plant – or you are risking root rot.
The bearded iris can live for many years. But after several years, the clumps become crowded, congested, and tangled with old and new growth. That makes August the perfect time to divide irises. This gives you new plants and freshens up and cleans up old ones. To divide, cut the foliage back to 6 inches, lift the roots and divide. Then replant with the top of the rhizome exposed to the sun.
2. Shasta Daisies
Shasta daisies have cheerful, white-petaled flowers with butter-yellow centers that contrast beautifully with the plant's dark green leaves. These perennials thrive in USDA hardiness zones 5-9 and require a site with sun – either full or partial sun – as well as well-draining soil. They are drought tolerant but do best if you give them sufficient water to keep the soil moist.
Shasta daisy (Leucanthemum x superbum) grows in clumps, and after 2-3 years, the clumps get tired and woody. Left to their own devices, these tired clumps won’t flower well in the spring. The solution is to divide Shasta daisy clumps in late summer or early fall. Dig up the entire clump, shake off excess soil and discard the woody, worn-out center. Split the rest of the clump with a sharp garden knife. Split the clump into several smaller sections, then replant them all immediately. Make sure that they are replanted at their original soil depth.
3. Common Yarrow
You may know yarrow plants as gordaldo, milfoil, poor man's pepper or thousand leaf. It’s also called plumajillo in the southwest – a term that means little feather in Spanish. The plant’s aromatic leaves are feathery and have a lacy texture. The yarrow stems can grow to 3 feet (1m) tall and are topped by flat clusters of tiny blooms - often yellow, cut sometimes white or pink.
Yarrow (Achillea millefolium) likes a sunny location in USDA hardiness zones 3-9. It grows in poor soil, clay soil, and even sandy soil, as long as it is well-draining. Yarrow plants need regular pruning and deadheading to keep the plant blooming. Even so, they get overgrown at summer’s end and benefit from being divided every few years or when the center of the plant begins to die out. Dig up the plant, discard the center and replant the outer chunks.
4. Hostas
Hostas are known as the queen of the shade garden and for good reason. These popular perennials have stunning foliage and thrive in shaded areas. Gardeners appreciate that hostas return year after year from their rhizomatous roots. They are available in many sizes - from teeny tiny to giant - and a wide variety of leaf patterns.
Hostas thrive in USDA hardiness zones 3-9. Although they prefer shade, some can grow in dappled sunshine. Hostas can get tired, tattered, and worn out by autumn. The beautiful foliage turns yellow or brown, and may sprawl or collapse as the plant prepares for winter dormancy.
Use an overcast August morning to divide hostas into sections, making sure each section has a healthy set of roots and shoots. Keep the pieces damp and you can store them for a few weeks before replanting.
5. Daylilies
Pretty, popular daylilies grow fast and live a long time. They are not true lilies, but are easy to grow, drought-tolerant and attract pollinators. The trumpet shape blooms appear in fiery shades of red, orange, yellow, purple, and pink, and are top choices for borders and edging. They thrive in USDA zones 3-10.
Daylilies are so easy to divide that they would be a great place for a beginning gardener to learn about propagation by division. They outgrow their space every three to five years. Wait until they finish flowering to divide them. This is usually the end of August.
Use clean, sharp pruners to clip the daylily foliage close to the ground before digging out the clump. Then divide the root ball with your fingers, move each one to a new location, and plant them so that the crown is just below the soil surface.
