Observe and Shop for Fall Color
Look around at public and private gardens right now to see which trees have the most flamboyant fall color. Some of the best are larch, tulip poplar, sugar maple, red maple, serviceberry, flowering dogwood, sweet gum, black gum, sourwood, sassafras, and beech. Autumn is a great time to buy and transplant deciduous trees and shrubs.
Pick and Choose Your Fall Cleanup
Some gardeners like to wait until spring to do their major cleanup, as spent foliage tends to act as a winter mulch. Still others like the clean-and-tidy look. Whatever your persuasion, it's important to remove and destroy any leaves or plants with disease or insects. Also consider removing faded annuals, weeds, and any perennial foliage or seed heads you don't find attractive. Leave ornamental grasses and other plants with winter interest alone until late winter, when they can be trimmed. Do not apply winter mulch until the ground is frozen.
Give Hardy Annuals A Head Start
Seeds of some annuals and biennials can be sown directly into the garden in the fall. These include larkspur, love-in-a-mist, cornflower, viola, calendula, nicotiana, foxglove, cleome, and forget-me-not. Sometimes they will sprout and over winter as plants, while other times the seed doesn't germinate until the following spring. Either way, you'll get flowers much earlier next year. All of these flowers will also self-sow. For a contained spread, gather the seed and replant where you want them.
Start Feeding Birds
For those of us who feed wild birds year round, it's always the right time to put out food, but if you feed the birds just in winter, it's time to clean birdfeeders thoroughly and buy fresh seed and suet. If you need new feeders, consider the kind that have squirrel baffles. In choosing seed, black oil sunflower is the most popular with the widest range of birds, but also consider some nyger seed for the goldfinch, and high-quality mixed seed for ground-feeding birds. Add some peanuts for the woodpeckers and nuthatches. Dry the seeds from your Jack-o-lantern and set them out, too.
Plant Garlic and Shallots
Fall is the best time to plant garlic, shallots, and multiplier onions. Some people even have success planting onion sets now. Onion family members are pretty adaptable as to soil as long as it is well-drained. For those member that grow in clusters or bulbs, separate them into individual cloves or sets. Throw away any that are soft or damaged. Plant with the blunt stem end down and the pointed tip up, covering with 2 to 3 inches of soil. Space them 4 to 6 inches apart and cover with several inches of a chopped-leaf mulch.