As Autumn approaches, many gardeners' thoughts turn to raking leaves. Yes, Fall is for raking and tidying up the remnants of the summer garden, but don't stop there! Fall is also an ideal time to plant not only bulbs, but also perennials, trees, and shrubs in most parts of the country. In fact, in regions with hot, dry summers, Fall is the preferred planting time.
Why Plant in Fall?
Air temperatures begin to cool down in Fall, but the soil is still warm. That creates the perfect environment for new plants: Much of their energy will be directed toward growing new roots rather than foliage. For many plants, roots continue to grow until soil temperatures drop into the 40s, meaning they'll have several months to get established and prepare for new growth the following season. Plus, in spring soil can be muddy, making planting unpleasant for gardeners and less than ideal for plants.
Doesn't the idea of getting outdoors and planting on a crisp Fall day — warmed but not baked by the sun — sound inviting? And, come spring, you can focus your efforts on planting annual flowers and vegetables.
You'll find a large selection of balled-and-burlapped and container-grown trees and shrubs at your local Home Depot Garden Center, as well as perennial flowers and herbs. Most trees and shrubs will still have some foliage, so you can get a better idea of what the plant looks like than in spring, when branches are often bare. If you're planting evergreens, get those into the ground as soon as possible since their roots must provide energy to the foliage all winter long. Deciduous trees and shrubs, on the other hand, go dormant and can be planted until the end of the month in many parts of the country.
Create a Cozy Corner Garden
If you're having trouble deciding what and where to plant, here's an idea. Close your eyes and imagine yourself on a chilly, late Fall day, sipping cocoa in a comfy lawn chair, watching the setting sun as you cozy up to a warm, outdoor fire. Now, open your eyes and evaluate your yard. Is there a place that gets late afternoon sun, where a few strategically placed shrubs might shelter you from the wind or provide a bit of privacy from your neighbors? Is the spot level? Could you create a simple stone patio large enough for a fire pit and a few chairs?
Landscape designers call plantings like these "garden rooms," extensions of your living space that use a variety of plants and outdoor fixtures to create an inviting retreat. Depending on your needs, you might plant several low-growing evergreen shrubs for privacy, a small deciduous tree to provide shade during summer, and a variety of perennials and bulbs to ensure color all season long. Read plant labels to make sure the mature sizes of the plants are suitable for the space.
Planting Trees, Shrubs, and Perennials
To plant trees and shrubs, dig a hole three times the diameter of the rootball and just deep enough so that when you place the plant in the hole the top of the rootball sits an inch or two above the soil line. Remove a container-grown plant from its pot and set it in the hole, or place a balled-and-burlapped plant in the hole as is, cutting through the burlap after the plant is in position. Backfill the hole halfway, water it well, then finish filling the hole and water again. As you backfill, keep checking to see that the plant is vertical and that its rootball is sitting at or just slightly above the soil line. It's important that you don't bury any part of the trunk.
Plant perennials in soil that's been amended with compost or other organic matter. Again, take care to set the plants so they sit at the same height as they did in their containers. Gently firm the soil around the plants and water them in.
After planting, apply an inch or two of bark mulch around plants to retain moisture. Plants should receive water weekly -- either from rain or from you -- right up until the ground freezes. Once the ground is frozen, you can apply a thicker layer of mulch to insulate plants from the freeze-thaw cycles that can heave them out of the ground.
Garden Clean-Up
Now that your new plantings are in place, evaluate your other gardens. There's no need to cut back perennials, except for aesthetic reasons. Many gardeners leave the dried foliage in place through the winter to help insulate the soil, waiting until spring to tidy up. Also, some plants' seed heads, such as coneflower and sedum, are attractive in winter and some will attract birds. If you do decide to cut plants back, leave a few inches of stem in place and take care not to damage the crown of the plant (where the stems meet the soil) because this is often where the buds for next year form.
The same philosophy holds true for fallen leaves that collect in garden beds — there's no reason, other than aesthetic, for removing them. Fallen leaves are nature's way of insulating the soil and adding nutrients as they decompose. In spring, if a thick layer of leaves still remains in the garden, you can gently rake them off and add them to your compost pile. (The exception is plants that have shown signs of disease — rake up their fallen leaves and dispose of them.) Fall is a good time to mark the location of perennials with labeled stakes so you'll know where plants are come spring and won't inadvertently weed them out or plant over them. It's also a good time to move or divide most perennials.
Unlike your garden beds, if your lawn is covered with a thick layer of fallen leaves, rake them up and compost them. The leaves can mat down over the winter and suffocate grasses, some of which continue to grow into late Fall and start up again in very early spring. However, if there's just a scattering or a thin layer of leaves, mow right over them to chop them up. The small pieces will decompose and add nutrients back to the soil.
