Avocado trees can be successfully grown in the southern low desert areas of Arizona. In the high desert and mountain plateau regions of Arizona, the cold weather will kill the tree if it is not brought indoors or grown in a protected area. Soil permeability is an issue in some areas of Arizona. In areas with low permeability and poorly draining soil, grow avocado trees in a raised bed or large container.
Locate the avocado tree in a warm part of the landscape with well-drained soil and protection from winds, if possible.
Perform a permeability if in doubt about soil drainage. Dig an 8-inch wide and 32-inch deep hole to test soil permeability and drainage. Add 5 gallons of water to the hole, wait an hour and add another 5 gallons. Check the hole after 24 and 48 hours for water remaining in the hole. Water remaining in the hole after 24 hours indicates the need to supplement the soil to improve drainage. If any water remains after 48 hours, plant avocado trees on a mound, raised bed or in a large container.
Remove existing grass and weeds from the ground around the planting site. Grass and weeds will compete with the tree for nutrients.
Supplement the soil with organic materials to improve drainage and fertility.
Choose a nursery grafted tree with healthy foliage that is between 2 to 4 feet tall.
Dig a large hole, 3 to 4 times the size of the container. Break up any solid layers of chalky white caliche, if encountered.
Place the tree in the hole and fill with the amended soil. Plant the tree at the same depth it was originally growing, and firm the soil around the tree.
Water the avocado tree immediately after planting and daily during the first week. Increase the time between watering to twice a week for the first few months, then to once a week.
Fertilize the tree with 1/4 pound of balanced fertilizer every 1 to 2 months during the first year. Increase the fertilizer to 1 pound per tree applied 3 or 4 times a year in subsequent years.
Use a nutritional spray three to four times a year. Apply iron chelates in the late spring and summer.
Cover the tree with blankets or a tarp whenever freezing weather is expected.
Pick avocados when the fruit is large and mature but still hard. Avocados ripen at room temperature after harvest. Some trees bear alternately, producing bumper crops one year and a sparse crop the following year.