How to Grow Lemon Trees in Arizona

Arizona's climate zones range from the low-elevation deserts in the southern part of the state to plateaus and mountain ranges in the central and northern parts that have cold, snowy winters. U.S. Department of Agriculture plant hardiness zones go from 4b through 10b. Grow lemons (Citrus limon) outdoors if you live within USDA zones 9 through 11. Otherwise, grow lemons in containers so you can move them indoors for winter.

Lemon trees grow well in hot summer, mild winter areas of Arizona -- the state is the second largest U.S. commercial producer of lemons. Lemons need well-draining soil, full sun and as frost-free an area as you can provide. If your neighborhood gets occasional freezes, plant the lemon tree in a warm part of your yard, such as against a south-facing wall, and be prepared to cover the tree if a frost is expected.

Because lemon trees grow throughout the year, they can have fruit, flowers and young fruit on the tree at the same time. The trees need regular watering, usually a deep watering every one to two weeks in summer and every three to four weeks in winter. But lemons vary in how frequently they need water, depending on the weather, the soil type and how fast they're growing.

Rather than putting your lemon on a set watering schedule, test the ground for moisture with a moisture meter or a soil probe, such as a long screwdriver. If the top 2 to 3 inches of soil are dry, water the tree. Don't let the soil in the root zone, which is the top 12 to 24 inches of soil, dry out. You can create a basin around the tree or use soaker hoses or drip irrigation. Apply deep, thorough waterings rather than shallow ones.

Lemon trees also need regular fertilizer using a citrus fertilizer such as 6-4-6 that's applied three times a year. Suggested timing for mild winter areas is to apply equal fertilizer doses in January or February, April or May and in August or September. Spread the fertilizer evenly under the tree branches, keeping it away from the trunk, at rate of 1 cup for every 24 square feet. Rake the fertilizer into the top 1 to 3 inches of soil and water the tree thoroughly.

Lemon trees vary in mature size, which means how far apart to space them depends on the variety. "Lisbon" (Citrus limon "Lisbon") reaches 25 to 30 feet tall and 25 feet wide, so space trees about 35 feet apart. Slightly smaller "Eureka" (Citrus limon "Eureka") grows to about 20 feet tall and as wide, with a spacing of 25 feet. A variegated lemon, "Pink Variegated Eureka" (Citrus limon "Eureka Variegated Pink") is smaller, 12 to 15 feet tall and wide, with a spacing of 20 feet. Smaller yet is "Meyer Improved" Lemon (Citrus limon "Meyer Improved"), thought to be a hybrid between lemon and an orange. It grows 8 to 10 feet tall and 12 feet wide, so space them 15 feet apart.

To grow lemon trees in containers, choose the smaller-growing lemon varieties, which won't attain their full size in containers. Young trees need at least a 5-gallon container, transplanting them as they grow until they're in a 16- or 20-gallon pot size. If portability is a consideration, choose lighter weight plastic pots over terra cotta ones. A "Meyer Improved" lemon tree may still set fruit even if it's kept totally indoors.

Use a commercial potting mix with ingredients such as peat, perlite, vermiculite and aged compost. It should be well-draining. Place containers in a sunny area. Fertilize with citrus food once a month from the time new leaves appear in spring until midsummer. Use 2/3 tablespoon of fertilizer for each 1 square foot of potting soil area, or according to the rates on the label. You can grow container lemons outdoors once all danger of frost has passed. Move them indoors before the first frost.