Harvest Brussels Sprouts
These little "cabbages" will continue to ripen and sweeten through the cold snaps so harvest whenever you're ready to eat them. If some of the sprouts get frozen almost solid, cook them right away or pop them in the freezer.
If you use raked leaves to top your annual veggie and flower beds or add them to the compost pile, speed up the decomposition process by mowing over them first with a lawn mower to shred them.
Inspect Indoor Plants Often
Plants that you moved inside for the winter might harbor insects, and it can take a few weeks before they become obvious. Check plants every week and isolate and treat any that have mealybugs, scale, spider mites, or aphids -- the most common hitchhikers.
Give Holiday Cactus a Dark or Cold Treatment
Christmas cactus needs either long nights or cool temperatures (or both) to initiate flower buds. You can put it in a closet or room that stays completely dark from sunset to sunrise until new flower buds reach 1/8 inch long (at least three weeks). Or move your plant to a cool location that stays between 55 and 60 degrees. Water just enough to keep the plant from wilting (the stems will feel limp), and hold off on fertilizer until buds form. Then move the plant into your living space and water whenever the soil is dry to the touch.
Don't Mulch Bulbs When You Plant
When you plant your bulbs, don't be too quick to cover them with mulch. Wait until the ground freezes, so you don't inadvertently provide a home for rodents that are looking for a place to hide for the winter. Once the ground freezes, the rodents will have burrowed elsewhere and it's safe to spread mulch. The same holds true for mulching trees and shrubs.