By October, garden beds need to be cleaned and last season’s annuals cut back.
Putting your garden to bed properly will result in a prettier, healthier garden this season and next. It’s essential to know what areas to clean, what to prune, what to leave undisturbed, and what to protect over winter. Simply taking a leaf blower to your beds and landscape is a start, but there’s more to the process, if you want to do it right.
Cleaning, Cutting, and Edging
When cleaning your garden beds, consider bed appearance, but also consider plant appearance and health. This means determining what should be cut back and cleaned and what should be left alone until spring.
Hardy chrysanthemums are perennials that don’t need to be cut back until the following spring.
Begin by cleaning out loose leaf material by hand or blower with a focus on the most visually conspicuous areas. Smart gardeners are wise to leave some leaf litter in beds to provide added winter protection for more tender plants and help support overwintering pollinators. (Some species of overwintering native bees, and butterflies use undisturbed leaf litter as essential winter habitat. Click here to learn more.) After clearing away unwanted leaves, give your fading garden plants needed attention.
Dead or dying annuals are the first thing to cut back or pull. If some have mature seed heads, consider scattering their seeds in hopes of getting a few self-starters in spring. Once annuals are removed and beds smoothed, start work on your perennials and shrubs.
Evergreens, such as lavender (back), should not be cut back.
Many perennials look great over winter and their crowns are protected by leaving the top growth intact through winter. Most ornamental grasses, lavenders, hardy salvias, hardy chrysanthemums, and rosemary are perennials that should not be cut back until spring. Exceptionally hardy perennials that die to the ground, such as daylilies, coneflowers, hardy geraniums, hostas, Shasta daisies, and asters, can all be fully cut back without worry. Some perennials produce seed heads that naturally feed overwintering songbirds, such coneflowers, asters, and hardy sunflowers, so it is nice to leave a few up. All healthy evergreen perennials and shrubs should be left alone.
Keep it Covered!
After cleaning and cutting back beds, cut fresh bed edges, and apply cosmetic mulch. [Click here to read more about garden edging.] Lots of mulches will work, but dark, earthy leaf mulch is like landscape gold. Not only does it look good, but it breaks down quickly to naturally feed soil, and it is easy to create from recycled leaves. [Click here to learn how to turn your fall leaves into leaf mulch.] Screened, partially composted bark mulch is another good option for broadcast mulching. For small garden spaces, Fafard Premium Natural & Organic Compost should be applied as a high-quality, fortifying mulch.
When mulching, work around perennials and shrubs. Many plants will die or perform poorly if their crowns and trunks are thickly layered with mulch. Succulents, alpine or rock garden plants, and Heuchera should never have heavy mulch applied on or around their crowns.
In fall, start by cutting back any dead, unhealthy, or crossing branches from trees and small shrubs. When pruning out dead, diseased, or infested wood, prune just below the point where growth is still fresh and healthy. If you think that a plant you are pruning is diseased, be sure to clean your pruning shears in a 10% bleach solution before pruning another plant. If additional pruning on flowering trees and shrubs is needed to shape the plants, first determine whether your shrubs bloom on old or new wood. It is okay to prune new-wood bloomers in fall but not old-wood bloomers.
Butterfly bush (Buddleja davidii ‘Dart’s Papillon Blue’) blooms on new wood and can be cut to the ground each fall. (Photo by Ptelea)
French lilacs (Syringa vulgaris), azaleas and rhododendrons (Rhododendron spp.), forsythia, most viburnum, service berries (Amelanchier spp.), and some hydrangeas, such as oakleaf hydrangea (Hydrangea quercifolia) all bloom on old wood—meaning they set their flower buds for the next year shortly after they bloom. These plants should never be pruned in fall, unless you want to cut off all of next year’s flowers. Old- or second-year wood bloomers are best pruned right after they flower. Hybrid roses (Rosa spp.), buddleja, crepe myrtle (Lagerstroemia indica), and some hydrangeas, such as wild hydrangea (Hydrangea arborescens), bloom on new wood, so fall pruning is an option.
Pruning techniques vary from plant to plant. As a general rule, shrubs that bloom on new wood are forgiving and can be hard pruned, or cut back nearly to the ground. In fact, hard pruning is often recommended for sprawling, aggressive bloomers like Buddleja. Rose pruning is another beast entirely and most recommended for late winter. [Click here to learn more about rose pruning.]
Toss it or Compost It?
Bed cleaning creates lots of waste. Some of the waste is perfect for composting and some is best discarded. Loose leaf matter makes great compost. Fall grass clippings and leftover edging pieces can also be thrown into the compost heap. Old perennial and annual waste can also be composted, if it appears to be clean and disease free. Healthy woody branches can also be chipped and added to the bin. Any material thought to have pests or disease should be thrown away. This is especially the case for vegetable waste, such as last-season’s tomatoes, which commonly develop early and late blights. Rose clippings should also be kept far away from the bin because of the many diseases these plants can harbor. [Click here to learn more about rose diseases and pests.]
Clean, coiffed beds, with crisp edges look great and will make spring prep a breeze. They will also make it easier to plan and implement fall bulb plantings and decorate for the winter holidays.
Grasses, such as this Ravennagrass (Saccharum ravennae) can be left up into winter.