Wrap Citrus Trunks
Citrus trees can suffer damage if temperatures drop below freezing. If you have young trees or live in a cold microclimate, loosely wrap trunks in multiple layers of frost cloth or burlap. This covering can be left on until mid-February or March when temperatures warm.
Continue Planting Cool-Season Herbs
In full sun, sow seeds for borage, caraway, chervil, chicory, cilantro, dill, fennel, lemon balm, and parsley. Transplant chamomile, mint, salad burnet, and sorrel.
Now that colder weather has arrived, stop feeding roses or tropical landscape plants such as bougainvillea and hibiscus. Feeding promotes tender new growth that is prone to frost damage.
There is still time to plant spring-blooming bulbs in garden soil improved with 4 to 6 inches of compost or well-aged manure. Bulbs prefer loose enriched soil so layer 4 to 6 inches of compost on top of the bed and turn it under before planting. Follow package instructions for planting depth, or as general guideline, plant bulbs two times their height from top to bottom.
Water Correctly to Prevent Root Rot
Plants require less water as temperatures cool. As a general guideline, water established desert-adapted trees, shrubs, groundcovers and vines every 14 to 30 days through December. New transplants usually require more frequent irrigation. Cold wet soil causes root rot, so skip programmed irrigations if it rains.