I'm new to the maple forum on GardenWeb, normally in the tropicals forums, but I have had a problem the last couple summers with my Japanese Maple. It has been growing extremely slow, almost not at all, and whole branches are dying off. Only about a third of the canopy came back this spring. I live in Southern Michigan, and during the summer we regularly see 80 and 90 degree weather. The tree is planted in a full sun location. From what I understand these are mountain trees that like to be kept cooler? That's the only thing I can think of is that we get too hot here in the summer for these trees. Any other ideas? Thanks