Answer: It sounds as though your buckeye is under some stress; winter damage, under- or over-watering, borer insects or even physical damage (weed wacker damage?) I'd inspect the area on the trunk where the bark is peeling. Peel back a piece of bark to see if you can find holes or tunnels in the wood. If so, you'll need to take a specimen to your local Cooperative Extension office for identification and control options; if you don't find any insect activity, clean the area of all foreign matter so the wound can heal itself. Leaf blotch causes diseased areas of variable size on the leaves. The diseased areas are at first discolored and water-soaked, later turning light reddish brown with bright yellow margins. If the entire leaf is affected it will dry, turn brown, and fall off. Leaf stalks may also be attacked. This disease looks very much like scorch. Rake up and destroy old leaves. No chemical control is available. Best wishes with your tree!
Q&A Library Searching Tips