Fertilizing Newly Planted Apple Trees

Newly planted apple trees require special attention where nitrogenous fertilizers are concerned. Lack of application, improper placement, or high rates can seriously damage young trees. Incorporating fertilizer into the hole at planting is not recommended because this practice can kill trees by burning young roots. Failure to apply nitrogen after planting can result in less-than-ideal growth. The rule of thumb when fertilizing new trees is to apply 0.02 pound of actual nitrogen per year in the orchard for the first 3 years. After this period, nitrogen application should be based on leaf analysis results and shoot growth. Any phosphorus or potassium as recommended by a soil test should have been applied to the field before planting and incorporated.

Follow the suggestions below for newly planted apple trees:

• Apply all fertilizer on undisturbed soil and keep the material 12 inches away from any disturbed soil (for trees planted by either auger or tree planter).
• If the nitrogen source is not critical, use whatever material is cheapest per unit of nitrogen. Table 1-9 lists the amounts of various nitrogen sources to be applied per tree to achieve the required 0.04 pound of actual nitrogen per year. If you use a source other than those listed, calculate the amount of material needed in the following fashion. First, multiply 0.02 by 1 (for a result in pounds per tree); or by 16 (for ounces per tree); or by 454 (for grams per tree). Divide the result by the decimal equivalent of the percentage of nitrogen in the material.

Example: You have a material with a nitrogen content of 46 percent. You wish to find out how many ounces to apply per tree before the beginning of the second growing season.

0.02 x 16 oz = 0.32 oz
0.32 oz / 0.46  = 0.7 oz
0.7 oz x 2 years  = 1.4 oz per tree at the beginning of the second year