Find 10 tips for cleaning up the garden this fall—including mulching, cutting back, improving soil, composting, dividing perennials, planting shrubs, and more. With cooler weather and fewer insects, it’s also easier to do this work in autumn, not during freezing temperatures. So let’s get going …
1. Maintain Your Perennials
Cut Back Flowers
If you have perennial flowers in your garden, some will need to be cut back after the first frost, while others can remain standing through spring to provide both winter cover for pollinators and seasonal interest to us gardeners.
- Plants including 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.
- On the other hand, perennials such as coneflowers and black-eyed susans have seedheads 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.
Divide and Conquer
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 grow 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 they grew previously, but space them apart to give them room to grow.
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.
2. Extend the Growing Season
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 those listed above. Flowers that can be planted now include statice, stock, sweet peas, pansy, lupine, sweet William, dianthus, calendula, carnation, and snapdragon.
3. Clean Up Vegetable Beds
Vegetables that have finished growing need to be cleaned up. It’s especially important to pull out any pest-infested vegetable plants or plants that were plagued by a fungal disease, like powdery mildew or blight. Do not compost diseased plants. Remove them and either burn them, discard them, or bury them where they won’t see the light of day for at least a year.
Some gardeners will leave plants that aren’t diseased because they provide overwintering sites for predatory beneficial insects. We leave that to your discretion. In some climates, having very wet foliage simply attracts white mold and disease.
4. Weed, Weed, Weed!
You may have thought weeding was over, but experienced gardeners know that weeding in the fall is the most important time! Never let any weeds remain in your garden beds, 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!
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 with which to work come spring!
5. Use Leaves Wisely
For a couple of generations, we seem to have forgotten the age-old practices of working 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.
However, leave some piles of whole leaves (not shredded) in corners of your yard 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 seed pod of milkweed plant.
When you mow your lawn, use a shredding mower, as it’s actually healthier to return that leaf litter to the soil. Leaves are liquid gold! You can put those shredded leaves in the compost bin to make nutrient-rich plant food or use the leaves as mulch to protect your garden soil over wintertime. See 8 Ways to Use Fall Leaves.
6. Start Composting (If You Aren’t Already)
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, nutrient-rich plant food. Layer your “brown” leaves with “green” materials in order to mix both high-carbon and high-nitrogen materials to get your compost heap cooking. Keep the pile slightly moist, and turn it once in a while to aerate and mix the material.
7. Plant Shrubs and Trees
The cool weather of October makes it the ideal time to plant most shrubs and trees. 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 it was growing 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.
8. Add Fall Bulbs for Spring Flowers!
Spring-flowering bulbs such as tulips, daffodils, snowdrops, allium, hyancinth, fritillaria, and crocus should be planted in 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.
9. Improve 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 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. Mulch for Winter Protection
Mulch is incredibly important for the winter garden! Keep young plants alive by covering the with mulch, spreading a 4- to 6-inch layer of shredded leaves, bark, or straw over the crown of the plant to protect it 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.
We also like to put a thin layer of leaves across smaller garden beds (or, plant a cover crop for large beds) to protect the topsoil and enrich the soil.
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 for the hose and drain it completely if you’re in an area where leftover water could freeze.
- 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.
- 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.
- Make sure that those bird feeders are cleaned up and ready for winter use! See more about feeding garden birds in winter.
And That’s It!
We hope that this list of fall garden tasks helps to set you up for a better spring!