When to Fertilize a Fruit Tree

Growing fruit in the backyard requires patience and attention to detail. Standard fruit trees take six to 10 years to produce a crop. Semi-dwarf trees take up to four years for production rewards. Dwarf varieties may bear fruit in as little as two years. Fruit trees require fertile soil with a pH of 6.0 to 7.0 for best results. As the natural shape of a fruit tree is not always the best for fruit production, pruning is an important part of the growing process. Fruit trees also require regular watering and cultivation, as well as a thick layer of mulch to keep the soil cool and moist during the dog days of summer.

Get the fruit tree off to a good start by using the proper planting technique, watering adequately and protecting the tree's fragile bark. These steps are more important at planting time than fertilizing. Adding fertilizer at planting time could burn the roots and destroy the tree. To plant a fruit tree, dig a hole large enough to fan out the roots. In most areas of the country, position the tree so that the bud union is 2 inches above the soil line. Shovel in loose dirt, firming every few inches to remove air pockets. When finished planting, water well to set the soil. To prevent damage from lawn mowers, weed trimmers and small animals, wrap the tree a commercially available tree guard, hardware cloth or chicken wire.

For best results in determining fertilizer requirements, have the soil tested. Check with the local cooperative extension agent for information about how to have the soil evaluated. If a soil test is not possible, apply 1 pound of a balanced 10-10-10 fertilizer around each tree the first year after planting. Fertilize in early spring before the buds open.

Fertilizing is not always necessary. If the fruit trees exhibit lateral growth of between 12 and 18 inches a year, fertilization is not required. If lateral growth does not happen in the second year, and a soil test is not available, upgrade the soil's makeup by applying 2 pounds of balanced 10-10-10 fertilizer per 2-year-old tree.

As fruit trees mature, their nutritional requirements increase. As with previous years, if growth remains below optimum levels, use with a balanced fertilizer, applying 3 pounds around each third-year tree. Start the fertilizer application two to three feet from the trunk and extend it to the tree's drip line, which is the point where the outer-most branches drip moisture onto the ground.

Maintain fertile soil by broadcasting 5 to 6 pounds of balanced fertilizer each spring around fruit trees that are at least 4 year old. Keep in mind that too much fertilizer hastens foliage growth and hampers fruit production. Never fertilize in summer because these applications may cause fragile late-season growth that can result in damage to the tree from harsh winter weather.

Nitrogen requirements differ with fruit tree varieties. For instance, apple trees set nitrogen easily and may need only 1 pound a year for favorable results. On the other hand, peaches and cherries may need as much as 5 pounds a year for bumper crops. Nitrogen is the first number in a fertilizer formula, with phosphorus the second and potassium the third. Consequently, a bag of 6-6-18 contains 6 percent nitrogen, 6 percent phosphorus and 18 percent potassium.