It’s critical to irrigate landscape plants during the growing season. Dry soil beneath trees and shrubs should be irrigated to a depth of twelve inches. Newly planted trees and transplants will require more frequent watering. Water should not be applied directly to the trunk. Instead, irrigate the root zone deeply.
Watering is best during the night, between 10 p.m. and 8 a.m. The second best time is in the later afternoon when temperatures are lower and foliage can dry before sunset. Mulch is also recommended. A three to four inch layer, placed from just off the trunk to the outer dripline, can improve moisture retention.
Water use should be monitored – over-watering can cause as many problems as drought. Drip irrigation systems or soaker hoses are recommended because they irrigate only the plant root zone, reduce run-off and decrease water loss to evaporation. They can also be set on timers to prevent over-watering.