Northern California Coastal & Inland Valleys
Move any tender potted plants, such as cymbidium orchids, to a protected spot under eaves or against a south facing wall until all danger of frost is past. Watch the local weather report, and if you hear that the temperature will drop into the twenties, cover bougainvillea and citrus with bed sheets or burlap. If frost damage occurs, wait until spring to prune. The frozen foliage will protect viable wood and pruning promotes new growth, which is most susceptible to frost damage.
Cool Season Annuals
It's still okay to plant cool season annuals so long as the soil is not saturated. Ornamental kale, nemesia and cilantro can be planted in cold weather. Add color to an otherwise winter weary garden with pansies, calendula, cyclamen or stock.
Feed Wild Birds
Migrating birds will appreciate a temporary resting place. Set out wild bird seed, available at pet, feed and some home stores, and the birds will reward your effort by cleaning up any remaining insect pests that may be lingering in your garden. It is very important for wild birds to keep their feathers clean in the winter months, so a shallow bird bath will be very much appreciated.
Clean Indoor Plants
Keep the foliage of indoor plants free from dust during the short days of winter. Even a light coating of dust will inhibit photosynthesis. Add a few tablespoons of non-fat milk to the cleaning water to create a nice shine to the leaves. Allow tropicals such as pothos and marantha to go slightly dry between watering, and give no fertilizer until the days start to get longer.
Indoor Cactus Care
Stop watering indoor desert cacti now. Cacti require a resting period during the winter months. Resume watering once you begin to see new growth, usually in February or early March. If you have done everything just right, you will be rewarded with cactus flowers shortly thereafter. Cacti should be fertilized with a product low in acid. Soils which receive no summer rainfall, usually west of the Mississippi, are alkaline rather than acid. Mimic nature and you will have success in gardening. Forest dwelling cacti such as the beautiful Christmas cactus require water all year around and also an acid fertilizer.