Prepare gardens for the cooler temperatures of winter.
TIP OF THE MONTH
Low night temperatures, from late November through February, can harm frost-sensitive plants. These include immature citrus trees such as lemon and lime, non-native cacti, and others such as bougainvillea, hibiscus, cape honeysuckle, tecoma, passion vine, potato vine and cuphea.
Precautions against frost damage include covering plants and tree with sheets, light blankets or hardware store frost cloth. Do not use plastic because it traps moisture and damages the plant. Cover plants at sunset and remove in the morning. Small outdoor lights may add warmth to trees that are difficult to cover. Cover tips of columnar cacti.
Keep plants irrigated (except succulents). Water acts as an insulator. Wet soils absorb heat during the day, protecting roots near the surface. Do not prune frost damage on plants — wait until new growth appears in the spring
Sow seeds for cool-season vegetables, such as beets, carrots, radishes, dill, chives, turnips, spinach, lettuce, kale, mustard greens, bok choy and Swiss chard.
Plant bare-root roses and deciduous fruit trees. Choose varieties proven to do well in the desert.
Most plants are dormant in the cooler weather and require less moisture. Monitor their water needs and adjust irrigation timers as necessary.
Water cool-season flower containers and vegetables twice a week.
Cool weather means harvest season for citrus. Test for sweetness. The longer fruit stays on the tree, the sweeter it becomes. Tangerines ripen first, followed by navel oranges, tangelos, lemons and limes.
Continue to harvest winter vegetables such as radishes, snow peas, spinach, arugula and leaf lettuce. Thin vegetable seedlings and enjoy in salads.
For compost, use disease-free yard debris such as leaves, lawn clippings and spent plants, as well as kitchen waste including fruit and vegetables scraps, coffee grounds and eggshells (no meat or dairy).
Apply mulch to plants to protect roots, retain warmth and prevent water evaporation.
Wait until April to cut back frost damage on tender plants such as citrus, bougainvillea and lantana. Remove mistletoe from mesquite trees.
Transplant cool-season color annuals such as snapdragon, stock, sweet alyssum, sweet pea, pansy, dianthus, Iceland poppy, calendula, evening primrose, lobelia, petunia, gazania, and geranium.
Set out transplants of broccoli, cabbage, cauliflower, Swiss chard, kohlrabi and onion sets.
Apply nitrogen to vegetables. Organic fertilizers are slower acting than chemical ones. Sources include alfalfa, blood meal, coffee grounds, cotton-seed meal, fish emulsion and bat guano. Fertilize the over-seeded Bermuda lawn once monthly.