Is Now a Good Time to Fertilize Shade Trees?

Apply fertilizer to the irrigated areas and just
outside the irrigated areas, just below the
soil surface, no deeper than this

Q. There are six trees on our property; a Raywood ash which is 10 years old, Arizona ash also 10 years old, California pepper (taller than our 2 story house and 8 years old), Bradford pear also 10 years old, a young African sumac and a young palo verde. Is now (October - November) a good time of year to deep feed these trees? Also, we've got a three foot long tree root from the pepper that's growing along the top of our lawn. Can I cut that part out this time of year?

A. You can deep root feed these trees (put the fertilizer in the root and watered area at about half a foot, no more) now that the trees are preparing for winter and stopped growing but they should still have green leaves on the tree.

            If there is no grass there then apply it to the surface of the soil and water it in. Water the fertilizer in the root zone three times over the period of one week and then continue to cut back on your irrigation for these trees as you normally would for the winter.



            The living green leaves on the tree will help move the water laced with fertilizer into the trees and into storage for next spring's growth. It also places fertilizer in the area of the roots for next season provided you don’t water too much. You can then skip a spring application of fertilizer.

            If the leaves have turned yellow or are starting to drop, you missed it for this year. Wait until next spring. There is no advantage to applying it in the fall vs. spring except possibly convenience.