In the low desert, transplant tomatoes between mid-February and mid-March, with frost protection. This provides extra time for plants to establish root systems and grow more plentiful foliage, and to get flowers blooming and fruit setting before summer heat arrives in late May. Tomato pollen is not viable over 90 degrees, so if you wait too long to plant, no fruit! At higher elevations, wait a few more weeks to set out tomato plants with frost protection.
Finish Transplanting Bare-Root Roses and Fruit Trees
Transplant bare-root roses and deciduous fruit trees through the end of the month. Container-grown roses can be transplanted up until April. Soak bare-root plants in a bucket of water for several hours or overnight before planting. If you can not get plants you've purchased into the ground immediately, be sure the roots are wrapped in moist peat moss and burlap (or similar) so they do not dry out. Dry roots are dead roots!
Skip an Irrigation
If you are lucky to receive decent winter precipitation, you may be able to skip a scheduled irrigation. Cold, overly wet soil promotes root rot in many plants, especially desert plants that are adapted to long dry spells.
Thin Root Crops
Beets, carrots, kohlrabi, onions, radishes, rutabagas, and turnips need space to develop to mature size. Thin periodically as needed, leaving space about one to one and half times the vegetable's ultimate size. You can eat what you thin as tender baby vegetables. If you thin a day or two after a regular irrigation, it is easy to pull without disturbing nearby roots.
Prepare for Warm-Season Gardening
It may be chilly outdoors, but warm season gardening is just around the corner. Sort through your seed stash. If it's old, do a germination test to see if seeds will sprout. Peruse seed catalogs for new varieties of warm-season cukes, melons, and squashes. Order early so you will be ready to start seeds indoors six to eight weeks before transplanting outside.