Answer: You are in USDA Zone 8. Thousands of beautiful and colorful plants will grow here! For landscape plants, you are better off choosing native and desert-adapted plants that will thrive in our alkaline soil, hot and freezing temperatures, drying winds, and limited rainfall. Trying to force non-adapted plants to grow here stresses them, and research shows that stressed plants actually attract pests and disease.
For annual flowers and vegetable plants, there are two growing seasons, a cool and a warm season, when different crops thrive. The cool planting season starts around late September or so with plants growing through April/May. The warm season planting starts in Feb/March and plants go until the heat, or some go through the summer. A good reference book that contains planting calendars for the low desert is called "Desert Gardening for Beginners: How to Grow Vegetables, Flowers and Herbs in an Arid Climate."
To grow annuals, you need to improve the soil first. Begin by incorporating plenty of compost. In sandy soils, compost improves soil fertility, water and nutrient retention. In clay soils, it improves fertility and drainage. Add a 4-6 inch layer of compost and incorporate it about 12-18 inches deep. Each planting season, add more compost.
After planting, add a 1-2 inch layer of mulch. Mulch is great to help retain soil moisture, reduce weeds, and as it breaks down it provides nutrients to the soil. Any organic matter can be used as mulch. Try compost, bark, wood chips, straw, or pine needles.
You might enjoy a visit to the Glendale Xeriscape Garden at the Glendale Main Library, the Desert Botanical Garden, and Boyce Thompson Arboretum (spring will have more bloom than late winter). Both DBG and Boyce have plant sales with species not easily found elsewhere. There are a number of other helpful books and magazines on desert gardening to help you choose plants.
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