Q: A couple of months ago I e-mailed and asked how I should fertilize my two-year old trees. You replied that I should wait until March to do this. Now that it is March can you tell me what to use and how to do it?
A: In general, ornamental trees should be fertilized only when you want to stimulate them to grow larger. If a tree has reached the size you want, no fertilizer is necessary if you are regularly fertilizing the lawn beneath or near the tree.
To help young trees grow faster, give them one tablespoon of 12-4-8 (or 16-4-8) per foot of height in March and again in July. For instance, if your trees are ten feet tall, you can give them ten tablespoons of fertilizer now and once again in three months. About one-third of the fertilizer should be applied beyond the drip line of the foliage since the roots of established trees extend out into this area.