Research Tree Varieties
If you plan to buy a live, balled-and-burlapped tree for the holidays, take some time to research what varieties are best suited to your yard. White pine and blue spruce are good choices but choose the planting site carefully, since they will eventually get very large.
Start Herb Seeds for Windowsill Garden
Start seeds of basil, chives, sage, or other herbs for a winter windowsill herb garden. If you don't have a sunny windowsill, consider setting up a light garden using fluorescent bulbs suspended a few inches above the tops of plants.
Avoid Chilling Houseplants
As nights grow colder, move houseplants away from window glass to prevent chill damage. Or close shades or curtains at night to help insulate them against the cold.
Evaluate Your Yard
Evaluate your yard for its fall ornamental value, and consider adding plants with attractive fall foliage, interesting shapes, and colorful berries.
Continue watering evergreens, as well as newly planted trees and shrubs, until the ground freezes. Evergreens continue to lose moisture through their foliage all winter, so keep soil moist as long as possible to send them into winter with plenty of reserves.