Plant Mums Now
Many gardeners grow chrysanthemums as annuals, discarding them when the growing season is over. But given the proper conditions, most chrysanthemums will overwinter and return next year. By planting them now, rather than waiting until fall, your mums will have plenty of time to establish a strong root system before the cold weather hits, increasing their likelihood of survival.
Set Out Fall Transplants
Set out seedlings of cabbage, broccoli, brussels sprouts, cauliflower, and kohlrabi. Keep new transplants watered; a soaker hose or drip irrigation makes this easy. Use a floating row cover to keep pests, such as cabbageworms, from making a meal of your little ones.
Sow Biennials Indoors
Indoors, start seeds of sweet William, forget-me-nots, lunaria (money plant) and English daisies. In addition, sow short-lived perennials such as columbine, hollyhock, Siberian wallflower, and foxglove. The seedlings will be large enough to set out in mid fall.
Stop pruning most trees and shrubs now, and allow roses to form hips. Pruning stimulates new growth that may not have time to harden off before the first cold snap of autumn. Leaving spent rose flowers so they form hips signals roses that they, too, should begin winding down.
Harvest Sweet Corn
Harvest sweet corn early in the day for the best flavor. Squeeze ears to see if they're firm, and wait until the silks have browned and dried to harvest. Eat immediately unless growing the supersweet varieties that will hold their sweetness for a few days. Store in the refrigerator.