Q: A mature hickory tree in my yard is dropping leaves. The leaves are not shriveled, spotted, discolored, or otherwise unhealthy looking. They are not the individual leaves, but rather a whole stem with several leaflets on the stem. Could it be that the tree is showing lack of water, or do I perhaps have a disease problem, and if so what should I do?
A: We don’t think of trees having brains but they do respond to environmental conditions in rational ways. In you case, the pecan had plenty of water and nutrients back in April so it put out lots of new leaves. Now that we have had weeks of dry weather, the tree has “reconsidered” its rash growth and has “decided” to drop some of those leaves. The leaves demand lots of water during the summer and the tree doesn’t want to over-extend itself.
Almost the same thing occurs with fruit trees. Hoping for a good year, the tree blooms and sets many more fruit in April than it can possibly ripen. During May or June, you’ll find dozens or hundreds of little fruit the tree decided to abort before they became a burden.
Windstorms and heavy rain will knock out more leaves but by June the tree will likely have achieved the balance of roots to leaves it prefers. Rake up your debris and add it to your compost pile.