Leaf analysis, observation of length and vigor of terminal growth, leaf color, and amount of leaf production should provide a continuing indication of tree needs. Nitrogen and zinc are the two plant food nutrients usually required by nut trees, especially pecan. The response of nut trees to phosphorus is very rare, and response to potash is uncommon. Several suggestions for determining the amount of fertilizer needed are listed. They do not all agree exactly.
Foliar analysis provides the best measure of the fertilizer needed.
Hole punching is not necessary and will likely cause unsightly clumps. Mature bearing pecan trees should make annual terminal growth of 5-10 inches. Younger pecan trees should make 12-36 inches of terminal growth until bearing starts. Poor nut production is expected from very weak or very long vegetative growth. Vary nitrogen fertilization up or down to obtain the desired tree response.