Vegetable Planting Calendar for Maricopa County

In the low desert regions of the southwest, including Maricopa County, most any type of vegetables and fruits can be grown successfully when appropriate varieties are selected and planted at the right time. The climate, the season, and potential pests all impact the selection of what to plant when.

High temperatures, both day and night for extended periods of time, low humidity, and the high solar intensity can put tremendous stress on plants. In addition, some plants may not survive freezing temperatures if there is a hard winter frost. Select varieties that are tolerant of temperature extremes, use local planting calendars that guide when to plant at the optimum times to avoid temperature extremes, or plan to protect the plants. Extreme soil temperatures affect seed germination and stand establishment. Use a soil thermometer to check for optimal soil temperatures to be in a range of 65° to 85°F for many of the commonly grown vegetables. It is possible to grow crops out of season by providing shade, more humidity, artificial heat, etc.

We have two optimal growing and planting seasons: one in the spring, the other in the fall. Both day length and temperature vary dramatically between seasons (short days and cold temperatures in winter to long days and extreme temperatures in summer). Since few annual plants are suited to thrive in both conditions, it is important to choose crop varieties that mature quickly to ensure a full life cycle within one season. Seed packets commonly provide a time to maturity for the crop variety.

Choose varieties that have been bred to be resistant to diseases and pests. These are indicated by initials following the plant variety name, for example, for tomatoes, “V” means resistant to Verticillium wilt disease, “N” indicates resistance to nematodes, “F” indicates resistance to Fusarium wilt disease, and “T” indicates resistance to tobacco mosaic virus. Choose a planting date to avoid known pest seasons. For example, delay fall planting until whitefly populations decline with cooler temperatures; delay spring planting until soils become warm and dry to reduce fungal and bacterial disease.

S = Seeds       T = Transplants     X = Sets of Cloves