Once your summer crop is spent, remove old vines and plants. If they are not diseased or infested in insects, incorporate them back into the soil. They will provide great organic matter making the soil richer and full of nutrients for spring planting. Now is also the time to add more organic matter to the soil such as compost, peat, leaves or manure. Till in a light dusting of ammonium sulfate along with the organic matter. Just make sure you do all of this prep work while the soils is still easy to turn.
If you have planned for a fall crop like carrots, beets and turnips, apply mulch over the plants to keep the soil insulated and workable; that will extend the digging season. After the first light frost, harvest pumpkins and winter squash—wait too late and a heavy frost could ruin the crop.
Pull up spent vines and foliage of annual flowers and compost them or dig them into the garden. If the plants are diseased, however, discard them in the trash. If you want to add fall color to the garden, choose pansies and snapdragons that can last well into colder months. Just make sure you plant them before the soil becomes too cold. Warmer soil allows the roots to become established and the plants to thrive.
Weeds are the bane of existence for amateur and master gardeners alike. They can choke out of healthy flower and vegetable beds and suck valuable nutrients from the soil. By the end of summer you’re ready to give up after fighting them all summer long. Fall can’t come a moment too soon—it’s the best time to rid your garden of weeds. They are much easier to remove once they’ve died off. Getting rid of them when they’re dormant reduces the chances you’ll be bothered with as many weeds in the spring.
Once temperatures hit freezing, your perennials will go dormant for the winter. To ensure they come back stronger and healthier than ever in the spring, cut the stems within a couple inches of the ground. Toss the cuttings just in case they are diseased so the same problem doesn’t rear its ugly head next year. Some plant varieties produce green leaves in the fall. Keep those and remove the brown growth and spent flowers.
Early fall is also the time to divide perennials that have become overcrowded. After two or three years, dig up the root mass and split the plant by hand, if possible. This will ensure you have a continuous supply of plants for you garden. In late fall after the ground freezes, loosely distribute mulch around the base of the plants to provide winter protection. Once spring growth begins, you can remove the mulch.
Cooler weather is the time to plant bulbs, so if you love early spring bloomers like crocus, daffodils and tulips, plant them in the fall. September and October are the optimum months to put bulbs, depending on your growing zone. Wait until there’s a definite chill in the air but do it while the ground is still workable.