Question
We live in East Texas and have a mature holly tree (I don't know what species) that I just noticed as yellowing leaves that are dropping.  This just started.  Am wondering what might be causing this.

Answer
If the leaves are on the lower branches or not near the ends of the branches this is normal leaf drop as the new growth comes on. If all the leaves are turning then it may be a disease. Fungicides can be sprayed on the foliage if the new growth is turning use a cooper based fungicide.