The tomato plant is a staple in the summer garden. In Arizona, however, tomato plants thrive in the springtime and die back in the summer. The Arizona soil is heavy clay and not as hospitable to tomato plants as soil in other parts of the United States. These obstacles needn't deter you from planting tomatoes in your garden. With the right care, tomato plants can produce a healthy, bountiful harvest in Arizona.
Amend the soil with compost early in January. Loosen the soil by digging down approximately 12 to 18 inches. Add compost or commercial soil amendment and turn it into the existing soil, adding approximately 1 inch of compost for every 12 inches of depth.
Plant tomato seedlings in late February when the night temperatures stay above 50 degrees F. Plant the seedlings deep into the soil; up to 1/3 of the plant should be buried below the surface to encourage strong root systems. Space the tomato seedlings about 2 feet apart.
Set up a system to support the tomato plants, using cages, trellises or stakes.
Water the tomato seedlings one to two times a week during the month of March. Water deeply, up to 2 inches in depth.
Add a side dressing of compost or commercial fertilizer in March when temperatures begin to warm and the plants begin to flower. Apply a 1/4-inch thick layer of compost to the left and to the right of the plant, leaving 4 to 6 inches between the stem of the plant and the compost. If using a commercial fertilizer, follow the directions on the label.
Increase the watering schedule to three times a week, if necessary. Continue to provide deep waterings on a regular schedule.
Monitor the plants for aphids and whiteflies, and apply organic pesticides as needed, following label instructions.
Harvest the tomatoes as they ripen and until they show signs of distress. Cut the plants back all the way to the soil and add the organic material to your compost.
Plant again in August for a fall harvest