Top 10 Questions About Garden Design

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(Image credit: Cheryl Ramalho)

Here at Gardening Know How we get lots of questions, and our goal is to provide answers to the best of our knowledge.

In this do-it-yourself era, we are often flooded with questions about garden design and layout. As a landscape designer, I have designed gardens and landscapes intended to serve all sorts of purposes, from purely aesthetic gardens to fully functional edible gardens to problem-solving gardens, such as rain gardens.

The following article includes the 10 most commonly asked questions relating to garden design.

1. How do you design a year-round garden?

The key to designing a garden that can be enjoyed all year is selecting a combination of plants with year-round interest.

This does not necessarily mean plants that bloom throughout each season. While in southern climates it may be possible to have blooms in the garden year-round, in cool northern climates, gardeners have learned to appreciate other attributes to create spectacular four-season gardens.

Think about adding plants specifically for their colorful leaf displays; seasonal color changes may also include twigs and branches, such as the bright red or yellow winter color of certain dogwoods. Choose plants that add unique textures, such as ornamental grasses, and/or trees and shrubs with peeling or interesting bark.

Plant shapes can also add interest to the garden. Gnarly, contorted, and twisted trees, like contorted hazelnut, can actually look more interesting after losing their foliage, while weeping, pendulous plants also provide year-round interest.

Lastly, consider plants with colorful early blooms, late-season berries and fruit, or attractive catkins or seed pods for spring and fall interest.

2. How do you plan a large garden layout?

Perhaps, the easiest way to plan a garden layout is to measure out the area and then sketch it out to scale. Most people use graft paper and pencil to do this. Your sketch does not have to be a masterpiece or award-winning design; it need only make sense to you. However, drawing it to scale will help you best utilize the space.

With large garden spaces, it can also help to break the area down into smaller gardens, divided by paths and walkways to make them easily accessible. Again,these smaller gardens should be designed specifically for your gardening style or needs. For example, if you're a heavy tea drinker, layout a space for growing your favorite herbs and perennials for tea.

If garden layout is truly not your cup of tea, there are also many books, magazines and websites full of garden designs you can use for inspiration and, of course, you can hire landscape designers or architects to design your garden.

3. Do raised container beds need drainage holes?

Traditionally, a raised bed is constructed as wood, brick, metal or stone boxes filled with soil to raise the garden above ground level for easier accessibility and/or drainage. Typically, the bottom of these boxes is left open to the bare ground, or constructed with a permeable material in the bottom such as stone or landscape fabric. The purpose of an open or permeable bottom is to allow for adequate drainage.

As raised bed gardening has gained popularity, there are many new ways to enjoy this gardening trend, from buying pre-made raised garden tables to repurposing old livestock water troughs, pools or tubs, or purchasing one of the beautiful new long-lasting metal beds in different shapes.

Whatever a raised container garden bed is made from, it will need to have drainage. The only exception to this rule is if you are actually growing water plants in it. In some cases, you may need to remove the bottom of a vessel or drill adequate holes in it to allow a raised container garden bed to drain properly.

4. How do I start a garden in a freshly cleared wooded area?

When planning a garden in a freshly cleared wooded area, you should begin by investigating and testing the soil in the garden. It's much easier to create proper soil conditions before a garden is planted than to try to correct soil problems in an existing garden.

Besides having the soil tested for nutrient levels, you should also test the site's drainage and map the sunlight in the area.

Starting a garden journal at this point can help you keep track of your findings, log your progress, as well as note your successes and failures. Before planting the garden, make any necessary soil amendments. Then plan out the garden based on plant sun or shade needs, plant heights and widths, and of course, plant texture and color.

5. What is distance apart for bedding plants?

How far apart to plant bedding plants depends on the plants and the look you desire. Before planting, determine each plant's mature width. This information can usually be found on seed packets or plant tags, but if not, you can always Google this information.

Next, decide if you want the plants to touch and form a mass or if you want formal spaces between plants. If you'd prefer each plant to have space around them, take the plant's mature width and multiply it by 1.5 or even 2 and space them that far apart. For example, a plant with a mature width of 12 inches (30 cm.) will have nice spaces between them if you plant them 18 to 24 inches (46-61 cm.) apart.

On the other hand, if you want the mass planted look, where the plants touch and grow together with no gaps, then plant them closer than their expected mature width. For example, if the plants mature to a width of 10 inches (25 cm.), planting them 8 inches (20 cm.) apart will ensure that they grow together. Plants can also be staggered for a fuller look. You can also calculate spacing using the square foot method of planting.

6. How much separation should there be between a septic tank and a vegetable garden?

Generally, plants with shallow roots can be placed around or even over a septic tank with no worries of the roots damaging the tank or its function. Most perennials, annuals and vegetable plants have shallow roots and will be fine with little to no space between them and the septic tank. You should, however, avoid planting trees, shrubs and other plants with larger,woody root structures.

When planting around or over septic tanks, bear in mind that you or septic tank servicemen may still need access to certain parts of the septic tank, and if the septic tank ever needs to be replaced, so will your garden.

7. Are the cement cinder blocks okay to use for raised beds?

Cinder blocks are a common material used for building raised beds. They are generally considered safe for use in gardens and around plants. However, there is some concern that cinder blocks may contain fly ash, a byproduct of burning coal. The concern is that fly ash can leach heavy metals into the soil.

Sadly, not much research has been done on the subject. It may be wise to take caution or thoroughly research the composition of the exact blocks you have before using them to create raised beds for edibles. There are also many other materials out there to make raised beds.

8. Which way to plant vegetable garden?

There is no right or wrong way to plant a vegetable garden. Where you plant your vegetable garden will depend on your site.

Most vegetables require full sun, but those that prefer light shade can be planted so that taller plants provide relief from the sweltering sun.

The days of traditional rectangular plots with perfect tidy rows are long gone. Today, garden space is utilized to its fullest potential by using techniques such as companion planting and succession planting. In both cases, plants are fairly close together to help each other grow or to take over once the original plant has run its course.

9. Can you lay plastic in the garden?

There are many good reasons to lay plastic in the garden. Most commonly, plastic is laid as a weed block, like landscape fabric. Some argue that plastic weed block is more harmful than helpful as it does not allow for the proper exchange of gases and may hinder the penetration of nutrients into the soil. Without the proper exchange of gases, earthworms and microorganisms in the soil may die out.

Another reason for laying plastic in the garden may be to kill off grasses or weeds by solarization- for this, thick clear plastic is usually used to intensify the sun's rays, essentially cooking the vegetation beneath the plastic. Black plastic, on the other hand, can also kill unwanted vegetation by blocking out the sun, not allowing weeds and grasses to photosynthesize. We recommend using biodegradable plastic if possible.

10. How to create privacy screening in the landscape?

Privacy screening can be created using plants in several ways. Naturally, you can just plant a row of tall arborvitae or other evergreens and enjoy your privacy behind them year round. Other tall plants can also create privacy screens or hedges, whether they lose their leaves or not. The privacy may not be as dense in the winter months, but many of us aren't out in the garden a lot in winter. Tall or wide trellises or fences covered in climbing vines can also create a beautiful privacy screen, as can bermed-up lushly planted beds or swales. Many garden retailers also sell decorative garden screens, and Pinterest is full of unique ideas for creating privacy in the garden, such as spacing unique old doors or other repurposed items in the garden.

We all have questions now and then, whether long-time gardeners or those just starting out. So if you have a gardening question, get a gardening answer. We're always here to help.

Darcy Larum