Q: We have a black walnut tree about 50 feet tall in the back yard. We got walnuts but they were small. Can I fertilize a tree that large?
A: Black walnut is a fun tree to own, if a bit messy in fall when the nuts drop. Fertilize it like you would a pecan tree. Measure the trunk thickness at breast height. For each inch, scatter four pounds of 10-10-10, up to a maximum of 25 lbs. under the tree branches. Do this in late March just before leaves appear. If you find an easy way to get the nutmeats out of the shell without smashing your fingers, let me know!