Apply Dormant Oil
Prune fruit trees such as apple and peach and apply dormant oil spray to suffocate overwintering insects (like scale) and their eggs. Spray on a calm day when temperatures are above 45 degrees F, and take care to coat both upper and lower surfaces of all branches.
Start Cool-Season Veggies
Start seeds of cold-tolerant vegetables, such as cabbage, broccoli, cauliflower, leeks, and onions indoors now to get a head start on the season. Cool-season crops can be ready for transplanting outdoors 4 weeks before the average date of the last frost.
Check Lawns for Moisture
Lawns are often forgotten during the cold winter months. Without adequate moisture, turf grasses can suffer severely and be dead by spring. If you have lawn on a slope in full sun, check the soil for moisture. If the soil is dry, and the temperatures are above 40 degrees F, set the sprinkler out -- regardless of the season.
The winter dormant season is one of the best times to start pruning deciduous trees. Remove crossing branches that may be rubbing each other, diseased and winter damaged branches, as well as weak branches that may break under the weight of snow. Make clean cuts and be sure to angle them slightly so water won't collect on the wound.
You can plant garden peas now if your soil is well drained and workable. Favorite varieties for the Pacific Northwest include 'Corvallis', 'Dark Green Perfection', 'Green Arrow', 'Oregon Sugar Pod', 'Snappy', 'Knight', 'Sugar Snap', 'Oregon Trail', and 'Oregon Sugar Pod II'. If mosaic virus disease historically attacks your peas, look for resistant varieties.