Dig Dahlia Tubers
Dahlias should be finished blooming by now. Cut remaining flowers from plants, and then wait for frost to kill the foliage. Cut dead foliage down to the soil line, dig the tubers, and store them for the winter in a cool, dry area in bags of slightly moist peat moss. Tubers can be separated now or left in clusters. I divide mine in spring, after new buds begin to swell.
Harvest Small Fruits
Harvest the last of the grapes and blueberries, and clean up any fallen apples and pears. Bruised fruit should be used right away. If you have a bumper crop of fruits, cook and freeze or can your bounty while it's still at the peak of perfection. Store apples and pears in a cool, airy place, such as a garage or protected porch. Apples, in particular, will last months with proper storage.
Watch for Standing Water
Watch for standing water in perennial beds after long periods of rain. Water that collects on the surface during winter will freeze, damaging perennials or causing the crowns of some plants to rot. Dig shallow trenches to help drain excess water away and make a note to raise those beds in spring.
Reduce Plant Disease
Reduce common perennial flower diseases, such as peony botrytis blight and hollyhock rust, in next year's garden by removing and disposing of all old stems this fall. This will reduce the number of overwintering sites of the disease-causing organisms, and you'll have less trouble with your plants next year.
A November application of fertilizer is very beneficial to lawns. It promotes root development without excessive top growth, and with a strong root system your lawn will be better able to withstand droughty conditions next summer. The best nutrient ratios for fall fertilizer are 3-1-2. Fertilizers formulated for fall application are often identified with the term "winterizer." Apply at rates recommended on the package.