As long as they are planted in good soil and receive plenty of water, fruit trees can thrive in the desert climate of Southern Arizona. Benefiting from mild winters and a long growing season, gardeners can harvest fruit throughout the year. Not all varieties of fruit trees do well in this climate, though. Some trees need cooler temperatures for a dormant state.
Select trees that suit the climate. Fruit trees have chilling requirements, the cumulative number of hours each winter when the temperature drops below 45 degrees. The requirements vary by tree. In Southern Arizona, fruit trees with lower chilling requirements, fewer than 600 hours per winter, grow better and produce fruit more consistently.
Choose an area with good drainage. The soil must have proper drainage or the tree will not be healthy and productive. This can be tested by digging a hole on the spot where you will be planting the tree, filling it with water and monitoring how long it takes to drain. Good soil drains in 24 to 48 hours.
Plant the tree. Dig a hole at least two times the size of the root ball and mix compost in with the existing soil as you plant. Go down deep enough so the root ball will be above the soil after planting and not dry out. Don't plant so deep that a section of the trunk is below the surface.
Connect the irrigation system to the tree. Wide, deep watering is beneficial for fruit trees. Create a basin several feet beyond the drip line of the tree, the perimeter below the canopy of the tree. Bring the irrigation line to the edge of the drip line and install a bubbler style emitter that will fill the basin.
Fertilize the tree. The tree is not fertilized at planting. Fruit trees should be fertilized in the spring just before the appearance of buds. Fertilizer is spread on the ground out to the edge of the drip line, then worked into the soil.