Autumn Cleanup That Works With Nature, Not Against It
May 26, 2022
Here are 10 autumn garden cleanup tips to reduce problems with pests and diseases—while also retaining homes and food for pollinators. There’s no need to get carried away in cleaning up every leaf. Let’s strike the right balance and work with nature!
1. Cleaning Up Vegetable Beds
Let’s start in the vegetable garden by removing all spent crops and residue. If left, these could serve as havens for pests and disease to carry over from this year’s crop to the next.
It is especially important to pull out any vegetable plants that are infested with pests or diseases like powdery mildew or blight. Do not compost diseased plants. Remove them and burn them, discard them, or bury them where they won’t see the light of day for at least a year.
Also, weed! You may have thought that weeding was over, but experienced gardeners know that fall is the most important time for weeding—even if frost has killed your flowers and veggies. The more you weed now, the less you’ll have to do next spring and summer. Water before you weed to loosen the soil and make your job easier!
Similarly, forking over the ground will help to expose grubs to the cold air and insect-eating birds.
If you are NOT sowing a winter crop and conditions are still mild enough, consider sowing a winter cover crop, or green mature. See cover crops for the home garden. Or, cover the ground with an organic mulch to protect it from winter weather.
Many gardeners will cover their beds with old carpet, tarp, cardboard, or landscape fabric to ensure that no sunlight gets to those weed seeds and that you have a clean slate on which to work come spring!
If you are growing cool-season crops such as spinach, lettuce, kale, cabbage, brussels sprouts, mustard, collards, or Swiss chard, be sure to protect them from a light frost with a bedsheet, grow cloth, or cold frame. Carrots, parsnips, and other root vegetables can stay in the ground. Almost all of these vegetables taste better after a light frost. See our handy chart on low temperatures for growing vegetables.
If you live in a frost-free region, October is a great time to plant more cool-season vegetables, including all of those listed above. Flowers that can be planted now include statice, stock, sweet peas, pansy, lupine, sweet William, dianthus, calendula, carnation, and snapdragon.
3. Maintaining Perennial Flowers
Leave ornamental borders uncut as long as you can bear. Many beneficial bugs shelter among old plant stems and seed heads, which also help to feed the birds. For most perennials, there’s no real need to cut back until early spring, when new growth emerges.
Perennials such as coneflowers and black-eyed Susans have seed heads that can be allowed to ripen until they turn brown and split open. These seed capsules are like salt shakers full of tiny seeds. Leave them for the birds and to self-sow to create more native flowers! Discover 20 self-sowing flowers.
On the other hand, there are some plants that should be cut back to avoid issues. Such plants as peonies, bearded iris, and lilies can be cut back to a height of 3 to 5 inches. Iris borers overwinter in/on the foliage, so removing it in the fall is a good idea. Learn WHICH perennials to leave and which to cut back.
Of course, always remove all diseased plant material from the garden. Wait until the first hard, killing frost and remove the diseased plants while they are still limp. Do not compost diseased plants, as diseases may persist in your compost pile.
Many perennials benefit from being divided every few years—including peonies, daylilies, Asiatic and oriental lilies, hostas, bearded irises, and upright sedum. You’ll know that a clump of perennials needs dividing when those in the center of the clump start to die out or when the plants’ flowers seem lackluster. To divide, just use a sharp spade to dig around the plant and lift it from the ground. Then, use your spade or sharp knife to divide the plant into smaller pieces. Replant them at the same depth in which they grew previously but space them apart to give them room to grow.
4. Mowing the Lawn
Just as we leave some perennials longer, you’re best leaving grass to grow a little longer over the winter. Soil-enriching caterpillars and other bugs bury right down into the thatch; a close-cropped lawn doesn’t do them any favors.
For this reason, set your mower blades fairly high for the final cut of the season. This will help to protect the soil and make your turf healthier, too. You can also take the opportunity to give your lawns a neat, crisp finish.
For a couple of generations, we seem to have forgotten the age-old practices of working with nature, not against it. We rake, mow, and leaf blow away every leaf and bit of nature that actually helps our gardens in the spring.
Certainly, rake leaves off paths and paving where they can make underfoot conditions slippery. But wherever you can, just let them be! A few out-of-the-way leaf piles, perhaps in the corner of your yard or under shrubs, provide invaluable habitats for overwintering pollinators. Butterflies will overwinter in a chrysalis hanging from a dead plant, native bees will “hibernate” in the hollow stem of a bee balm plant, birds will flit around spent sunflowers, and caterpillars will roll into the seedpod of a milkweed plant. (Leave the leaves whole; do not shred.)
VIDEO: How to Tidy Up Your Garden and Help Wildlife at the Same Time
In our video, we demonstrate many of the gardening tips listed in this fall cleanup guide. See how it’s done!
6. Composting Leaves (If You Aren’t Already)
Put some of those shredded leaves in the compost bin to make nutrient-rich plant food! Fall is the best time to start a compost pile. Why? You’re cutting down dead foliage, weeding, and shredding leaves, which all combine to make wonderful free fertilizer for the spring.
For faster composting, layer your “brown” leaves with “green” materials in order to mix both high-carbon and high-nitrogen materials. Keep the pile slightly moist and turn it once in a while to aerate and mix the material. See how to get your compost heap cooking.
7. Planting Shrubs in Fall
In all but the coldest regions, midfall is a great time to plant wildlife-friendly bushes and hedges. Include berry species like winterberry, which birds love, and pussy willows, which support butterflies. See the best shrubs for the birds.
The soil is still warm and plants have time to get established before kicking off new growth in the spring. To plant a shrub or tree, dig a hole slightly larger than the root ball of the plant, set the plant in the hole at the same height that it was growing at in its nursery pot, mulch, and water.
For established trees, slow down any watering in early fall; once the trees’ leaves have dropped (but before the ground freezes), give all trees and shrubs a deep watering, covering the entire area under the canopy.
Plant by late October into early November. Larger bulbs are best planted 8 inches deep; smaller bulbs, 4 inches deep. Bulbs are best planted in groups or beds of the same color, but you can also scatter bulbs across your perennial beds for pops of color in early spring. If deer are a problem in your area, avoid tulips. Stick to daffodils and allium and crocus.
Speaking of bulbs, be sure to dig up tropicals such as cannas, dahlias, elephant ear, caladium, and gladiolus before a hard freeze arrives!
9. Improving Soil in Fall
Soil must be replenished, and fall is the BEST time to do this for a healthier garden next year. After your garden has gone dormant, add organic matter to your soil—such as compost, rotted manure, or shredded leaves. Mix lightly into the top few inches of your beds so that when spring arrives you can plant immediately without worrying about working the soil during wet weather.
Tip: If possible, use a sharp spade to turn your garden soil. Tilling is fine for large gardens, but it can move pests and diseases from one section of your garden to another.
Autumn is also a great time to get a soil test to see if your soil is lacking in nutrients or has a pH that isn’t ideal for growing the plants that you have. Call or email your local Cooperative Extension, which typically provides free or low-cost soil tests, or purchase a test kit from your local home improvement store or garden center. If the test shows excessive acidity, you’ll want to apply lime. If your soil is too alkaline, you’ll apply sulfur. See how to test your soil.
10. Mulching for Winter Protection
Covering the ground with organic mulch protects it from winter weather. Spread a 4- to 6-inch layer of shredded leaves, bark, or straw to protect plants from freeze-and-thaw cycles. In the early spring, just as the plants break dormancy, gently rake the mulch away and spread it throughout your bed to keep weeds at bay during the summer.
However, for fruit trees and berry bushes, we prefer to delay mulching until the end of winter. This means that once all of the leftover leaves are raked up, frost will have a clear run, penetrating down into the top layers of soil and cleansing it of overwinting pests lurking there.
Tip: If you are mulching newly planted trees, NEVER mulch right up against the trunk. Leave a 6-inch gap around the base of the tree. Otherwise, the mulch might camouflage mice or voles gnawing on the bark over the winter.
A Few More Items for the Fall To-Do List …
Before it gets too cold, take care of your garden shed, pots, tools, and equipment.
Turn off the water to the hose and drain it completely if you’re in an area where leftover water could freeze.
Pumps and fountains should also be removed, cleaned, and drained before storing.
If you have a lawn mower or string trimmer, drain out the gas.
Clean, sand, and oil your garden tools before storing them for the winter.
Clean out cold frames if you use them for a head start on spring vegetable growing.
Remove canes and other plant supports; wipe off soil with soapy water, let them dry, and store dthem in a shed or garage.
Bring ceramic and clay pots inside, or they may crack in freezing temperatures. Dump the soil on your garden bed and sterilize the pots with a diluted bleach solution.
Don’t stack pots; it’s hard to get them unstuck in the spring.