Fertilizing

Nut trees growing in deep, fertile soil may produce satisfactory crops without fertilizing; in other soil, annual fertilizing is needed. Apply fertilizer to the soil surface under the spread of the branches, keeping it at least 1 foot away from the trunk. Apply in early spring before growth starts.

Nitrogen is the element needed in greatest quantity. Lesser amounts of phosphorus and potassium are required. A 20-10-10 or similar analysis mixed fertilizer high in nitrogen is suggested. (If 20-10-10 or similar analysis mixed fertilizer is not readily available, substitute 1 pound of 12-12-12 plus 1/3 pound of 33-percent ammonium nitrate for each pound of 20-10-10 suggested.) For young trees up to 6 inches in trunk diameter, apply 20-10-10 at the rate of 1 pound per inch of trunk diameter at breast height. The diameter of a trunk is approximately one-third of the circumference. For example, apply 6 pounds of 20-10-10 to a tree that is 6 inches in diameter (18 inches around the trunk) at breast height. For trees from 7 to 12 inches in diameter, apply 2 pounds of 20-10-10 per inch of diameter. For large trees more than 12 inches in diameter, apply 3 pounds of 20-10-10 per inch of diameter.

These are general suggestions. On infertile soils it may be helpful to increase the quantity of fertilizer by 25 percent. On fertile soils, the quantity of fertilizer may be reduced by 25 percent or more, depending upon the vigor of the tree.