Loquat tolerates many soil types but prefers non-alkaline soils. The soil should have moderate fertility and the tree needs good drainage. Allow sufficient room for the tree to reach its full growth without crowding. Typically, a loquat is 6 to 8 feet tall and wide at five years old and 12 to 15 feet tall and wide at 10 years old. It can grow 36 inches per season. Loquats can live 50 to 150 years. CalPoly San Luis Obispo University notes that a loquat in Southern in California measured 36 feet tall and 34 feet wide.
Water Requirements
Water the newly planted tree regularly and deeply during the first year it is in place to establish the root system. Water the new tree every other day for the first week, then go to one or two waterings weekly for the first two months. If periods of over five days without rain occur during the tree's first three years, water the tree once a week during the drought. Loquat can tolerate drought once established, but grows best with regular irrigation during its lifetime, especially during the summer. Keep water away from the trunk of established trees, keeping the irrigation zone from about half the distance between the trunk to the tips of the outermost branches. Conserve soil moisture and prevent weeds by applying a 2- to 6-inch-deep layer of mulch such as bark around the tree, keeping it 8 to 12 inches away from the trunk.
Light and Temperature
Situate loquats in full sun. They'll tolerate partial shade but flower and fruit production lessens. The trees are hardy in U.S. Department of Agriculture plant hardiness zones 7 through 10, but flowers and fruit are damaged by temperatures around 26 to 28 degrees Fahrenheit. You can grow loquat as an ornamental in colder parts of its hardiness range, but you won't get fruit. The loquats need heat to ripen well. Where fruits experience cool summers, they don't form as much sugar and aren't as tasty. High summer temperatures and drying winds can cause leaf scorch and sunburned fruit.
Fertilizer Needs
Loquats benefit from regular, light fertilizer applications. Overfertilization reduces flower production. For young trees, spread a shovelful of manure around the tree in the fall. In addition, every month or two, scatter a tablespoon of a fertilizer such as ammonium sulfate around the tree and water it in. For mature trees, apply ammonium sulfate or calcium nitrate evenly over the irrigation zone of the tree. Use 1 pound of fertilizer for every 1 inch of trunk diameter and water the fertilizer in.
