Citrus trees are abundant in their offerings to desert gardeners, with lush evergreen foliage, fragrant flowers and decorative, tasty fruit. High heat required by most citrus is easily met in the Coachella Valley. Full flavor and juiciness develop better here than almost anywhere.
Citrus plants need deep, well-drained soil. In frost-free areas, they can be planted any time. In colder parts of the valley, wait to plant in Spring after danger of frost has passed (March 15).
When planting more than one tree in an average-sized garden, space grapefruit 20 feet apart; most other citrus 15 feet apart. Plant in the warmest location available – in full sun or with some afternoon shade.
Build a basin around newly planted plants at least 4 feet in diameter with sides about 6 inches high. For March-planted trees, fill basin and soak soil to 2 feet deep at least twice a week from March to May. Soak to 3 feet deep about twice a week June through September. Extend watering frequency to every 10 to 12 days during winter months. By March, the tree can be considered established and can be irrigated as a mature tree.
Source: Lush & Efficient