Amend Garden Soil
Cool-season planting is at hand. Improve garden soil by adding a 4- to 6-inch layer of compost. Dig it into the soil to a depth of 12 to 18 inches, along with fertilizer containing nitrogen and phosphorous (desert soils have plenty of potassium so it doesn't need to be added). You can also incorporate soil sulfur (3 pounds per 100 square feet) to improve drainage in clay soils.
Transplant Landscape Plants
Transplant desert-adapted trees, shrubs, vines, ground covers, perennials, cacti, and succulents. Fall planting provides seven to eight months of moderate temperatures, allowing plants to establish and grow a strong root system before summer. There is no need to add organic matter to the backfill, just dig a hole that's only as deep as the rootball and 3 to 5 times as wide. A wide hole helps roots spread outwards through the soil.
Plant Cool-Season Vegetables
Sow seeds for root crops such as beets, carrots, kohlrabi, leeks, onions, parsnips, radishes, rutabagas, and turnips, as well as greens such as celery, chard, collards, endive, leaf lettuce, mustard, and spinach. Cole crops can be sown from seed or transplants. Try bok choy, broccoli, brussels sprouts, cabbage, cauliflower, Chinese cabbage, and kale.
Start Cool-Season Culinary Herbs
Sow seeds for chives, cilantro, dill, fennel, and parsley. Set out transplants for lavender, lemon balm, marjoram, mint, oregano, rosemary, sage, and thyme. Plant in soil with excellent drainage because herbs don't like wet roots.
Initiate Reblooming of Christmas Cacti
It's time to prepare Christmas cacti for repeat bloom during the holidays. They need a period of darkness to set flower buds. Put them in total darkness for 12 to 14 hours daily for two months. Place a cardboard box over them in a closet and take them out during the day. Water when the top of the soil is dry. Use a phosphorus fertilizer to promote flowering.