Juicy red tomatoes still warm from the sun beat out tasteless unripe green tomatoes from the grocery store any day. With Arizona's mild desert climate you can grow and harvest tomatoes nine months out of the year. Starting tomato seedlings inside under grow lights in January gives the garden a head start. Most of Arizona has hot summers with little rainfall and the soil is alkaline. Overcome those challenges to grow tasty tomatoes nearly every day.
Prepare the soil. Dig a hole 2 feet deep and 2 feet wide. Remove any rocks. Add the removed soil to a mixture of 2 cups of gypsum, fertilizer according to package directions and two 2-gallon buckets of compost or organic matter. Distribute the mixture evenly throughout the removed soil and refill the hole.
Plant the tomato. Remove any leaves or side branches from the main stem for at least 6 inches from the root ball. Tomatoes need lots of roots to get through Arizona's hot summers. The plant will grow new roots from any area under soil. Dig a small hole a few inches deeper than the root ball and as long as the area of the stem where you removed the leaves. Lay the plant on its side with the root ball in the hole. Cover the roots with soil and the stem area. The plant will look like it's lying on its side but in a few days the top will right itself. Water well.
Fertilize the plant every two weeks with water-soluble fertilizer. This is more often than you would fertilize in other areas, but in Arizona you need to water every other day from May through September, and all that water flushes some of the fertilizer away. Use an irrigation system or soaker hose so the water gets right to the roots, minimizing evaporation. How long and often you water depends on the weather. One gallon every other day usually works well.
Stake plants to keep fruit off the ground. As this exposes the fruit to the harsh Arizona sun, leaving the plants un-staked provides shade. Yellow spots indicate sun-burnt tomatoes.
Shade plants during the hottest part of the day during warmer months. Temperatures in the Arizona desert easily can reach over 100 degrees every day during the summer. Ensure the tomatoes receive afternoon shade or set up a system using a tomato cage and shade cloth.
Hand pollinate the tomato flowers early in the morning when daytime temperatures get above 95 degrees F. The pollen dries out quickly and loses its ability to fertilize. If you don't hand pollinate, you may not have tomatoes during June and July.
Cut back plants to about 1/3 their size in mid-August so they throw out new growth, giving you a second crop during the fall and winter. If there is no frost, tomatoes may keep producing through the winter.