This tree in our yard next to the house is old I think but there's something wrong with it. I know worms keep eating the leaves so it's a wonder the tree still thrives. This evening I found something new; looks like hard knots on a great number of the leaves! What's wrong with it??? 😰
They are galls caused by a midge, a tiny fly, which disfigure the leaves but won't kill the tree.
If the tree is not vigorous, you might want to have an arborist look at it and follow their recommendations.
