Citrus trees require the warm sun and well-drained soils of USDA hardiness zones 9 through 11, where the temperatures do not fall below 20 degrees F. If you are an Arizona gardener, your state resides within hardiness zones 5 through 10a. While you will not be able to grow citrus trees throughout the entire state, you can have great success growing citrus in Tucson, Deer Valley, Phoenix, Parker, Mesa, Yuma, Bullhead City and their immediate surrounding areas.
Plant your citrus trees in September. Choose a sunny location that has plenty of wind protection, if you live in Arizona. Planting the citrus trees on a slight slope will allow cold air to flow downward past the trees. Planting against a wall will also protect the citrus from winds.
Make sure that the holes for your citrus trees are three to five times wider than their root balls. Wider holes will promote the outward growth of the citrus tree's roots, which is essential to the health of the tree.
Water the citrus tree heavily during the first year of planting. Arizona receives much of its rainfall during the latter part of summer, so supplemental watering is usually necessary. Water to a depth of 3 to 4 feet using a soaker hose. Water once every three days during the summer and every six days during the winter.
Water less often once the citrus trees are established. After the first growing season, Arizona's average annual rainfall of 12.7 inches is usually not enough to sustain the citrus trees. Therefore, deep watering with a soaker hose, once a week during the summer and once every three weeks during the winter, may be necessary.
Fertilize your citrus trees during the months of January and February and then again during April and May. Do not fertilize the citrus trees after August in Arizona. This will give the trees an opportunity to go dormant during the winter. Apply the fertilizer per label instructions.
Trim your citrus trees in the spring. Remove damaged or dead branches using a pair of pruning shears or a pruning saw. Remove branches that grow inward, in order to give the citrus tree a groomed appearance. Apply a whitewash to the cut areas of the citrus trees using a paintbrush. Covering the cuts will help protect the citrus trees from the strong Arizona sunshine.