Apply Horticultural Oils
Horticultural oils suffocate insects and larvae that are overwintering on the bark of dormant trees and shrubs. Apply them on a calm day when temperatures are above 40oF. Be sure to cover all surfaces of the plant with spray, from ground level to the tips of the branches.
Build a Cold Frame
If you're growing cool-season veggies such as arugula and spinach, you can help protect your crops from cold snaps by building a simple frame of PVC pipe and draping clear plastic over it. The plastic will trap heat, so prop the frame up with stones on clear days to allow cool air to enter to prevent plants from burning and to let excess moisture evaporate.
Protect Container Plants
An easy way to protect the roots of outdoor container plants through winter is to sink the pots into the ground to the top of the lip. Another method is to place the pots inside larger pots and then fill the void between the pots with dry potting soil. The air space between the pots will help maintain suitable temperatures for the roots.
During the busy holiday season it's easy to forget that houseplants besides the holiday gift plants need regular care. Check soil moisture every few days by sticking your finger into the soil. If it's dry to the first knuckle, water. Also, mist your plants to combat the drying effects of overheated rooms.
Bagworms feed mainly on evergreens, though they can be found on many deciduous trees and shrubs. Now is a good time to control them. The pests live in "pine cone-like" cocoons that hang from foliage. Bagworm eggs overwinter in old "bags" and hatch in June. New bagworm larva move throughout the plant and feed on leaves and needles. Control can be a challenge, as bags are difficult to penetrate with sprays. Hand picking is the easiest way to remove the bagworms, especially in winter or early spring before the eggs hatch.