Fruit trees that are actively growing generally need 1 inch of water once a week, or about 2 gallons of water per square foot of root space once a week. (The roots generally spread out somewhat farther than the top canopy of the trees.) A newly planted tree would have a root spread of up to 2-square feet and, therefore, would need 2–4 gallons of water a week. Adjustments can be made for rainfall and soil type. Your tree may need water quite often in very sandy soil, less often in heavier soil. Always dig down a few inches into the soil first to see if watering is necessary. Trees in a lawn area should have a deep soaking about twice a summer in addition to normal lawn watering.