I'm really dont know much about trees and landscaping, just lawncare. But a customer of mine has a japanese maple that is dying for no apparent reason. He says it has always been a healthy tree up until this spring. I cannot find any signs of insect damage, but about a third of the tree has died and the rest of the leaves are weak and have small brown spots on them. Any suggestions on what to do, or Ideas as the what the cause might be?