Irrigate all fruit trees thoroughly as needed to maintain adequate soil moisture. Apply water around mature trees in a broad band beginning one-third of the distance from the trunk to the tree's drip line and extending out beyond the drip line a few feet. Apply enough water to wet the soil at least two feet deep. Remove grass and weeds from soil under the tree's canopy and then add a layer of coarse organic mulch to conserve moisture. Keep mulch at least one foot away from the trunk to protect trees from crown rot. During the summer, wash trees periodically with a forceful spray of water to remove dust, honeydew and pests like aphids, whiteflies and spider mites.