Hi, I have an oak tree I bought from the nursery 2 years ago. Its about 10 feet tall now. The other day, I noticed the leaves are getting brown spots on them (see attached pictures). I never noticed this in the first year but it could have been there. Anyone know what it is and how I can treat it? Thanks!
After quite a bit of reading, I found out what is causing it. Not sure if you are allowed to post links on this forum but I came across an article on an insect called the Oak Leaf Phylloxera whose damage is often is often misdiagnosed in the late summer as fungal Anthracnose. The bug is a tiny 2mm white speck on the underside of the leaf and it sucks sap from the leaf creating brown spots. Sure enough, my leaves had the bug (very hard to see them if you do not look VERY close). I sprayed my oak with an insecticde soap (luckily the oak is only 10 feet) and I'll see how it does. http://www.isaontario.com/pages/Resources/phc/02Nov_oak.php
