What to do in your garden in December
Cool-season color. Sunset climate zones 10-13: Set out transplants of calendula, chrysanthemum, cyclamen, dianthus, Iceland poppy,Johnny-jump-up, pansy, petunia, primrose, snapdragon, and sweet alyssum.
Cool-season crops. Zones 10-13: Set out transplants of broccoli, cabbage, cauliflower, kohlrabi, and onion seedlings. Sow seeds of beets, bok choy, carrots, chives, collards, dill, fennel, green onions, lettuce, radishes, spinach, and turnips.
Living Christmas trees. Zones 1a-3b: Consider Colorado spruce (Picea pungens) and Douglas fir (Pseudotsuga menziesii). Zone 10: Try Arizona cypress (Cupressus arizonica), Colorado spruce, deodar cedar (Cedrus deodara), Douglas fir, and piñon (Pinus edulis). Zones 11-13: Good choices include Afghan pine (P. eldarica), Aleppo pine (P. halepensis),and Italian stone pine (P. pinea). During its indoor stay, care for the tree as suggested at left. After the holidays, transplant it outdoors.Subtropical Norfolk Island pine (Araucaria heterophylla) can be grown indoors year-round.
Apply dormant spray. To smother overwintering insect pests(aphids, mites, scale) and their eggs, spray deciduous fruit trees and roses with dormant oil after their leaves fall. Spray the branches, trunk, and the ground inside the drip line.
Care for poinsettias. Place the plant in a brightly lit room, away from cold drafts, heater vents, and direct sunlight.Water when the soil surface feels dry, but never let the soil get soggy or allow water to pool in the saucer.
Protect citrus trees. Zones 12, 13: When temperatures below28° are forecast, irrigate trees deeply, then cover the canopies with burlap, blankets, or old sheets.
Refurbish tools. To clean spades, trowels, and such, fill a5-gallon bucket with sand and mix in 1 quart of vegetable oil (such as canola). Plunge the metal tool heads into the sand several times until clean. To remove rust spots on pruners and saws, gently rub the blades with sandpaper. Sharpen blades with a whetstone, spray them with machine or mineral oil, and wipe clean. Rub wood handles with linseed oil.
Spread winter mulch. Zones 1a-3b: Spread a 3- to 4-inch layer of organic mulch over beds of bulbs and perennials to protect their roots and prevent plants from being heaved out of the ground during freezing and thawing cycles.
Assemble luminarias. Also called farolitos, or little lanterns, luminarias are easy to make.Fold down the top 2 inches of a paper lunch bag, and then pour in 2inches of sand. Place a votive candle or tea light in the middle of the bag, tapping it into the sand. Set the open bags 2 feet apart along paths, driveways, or patios.
Create a botanical wreath. Gather materials from your garden and local craft shops to make a wreath. Using florist’s wire and hot glue, attach bay leaves or snippets of dalea, eucalyptus, or juniper to a wire wreath frame. Fill in with clusters of oregano, sage, and thyme, rosemary sprigs, and seed pods of carob, mesquite trees, or Texas ebony. Finish with accents such as dried chiles, devil’s claws (Proboscidea louisianica), pomegranates, or yucca pods.