Many times trees have grown in poor soil conditions where feeding and fertilization can help the tree remain healthy. Spreading commercially available fertilizers around the base of the tree doesn’t put the material where it’s needed – in the roots themselves.
Boring holes around the tree to reach the root structure, and placing the fertilization granules where the roots will get it is what is needed. To give your trees nutrients where the roots can best use them, consider going beyond common topical fertilizer and having a professional fertilization procedure done.
Your tree will thank you!