Perhaps the rootball has dried, in spite of the efforts to water it?

Stick a finger in it to determine if it's moist or dry.

We have had some very hot and humid days in Aug in the north east and this may be part of the problem. Many of my maples planted in the garden have shown signs of heat stress this year. The other factor to consider is how much wind the tree is exposed to. This will dry out the leaf surface and make the leaves curl. I have a few of these growing in full sun at the shore and they are not showing stress. Good luck with your tree; it is one of my favorites.

Ed

It is not a dried out rootball, as far as I can tell. I'm very disappointed, because we were looking forward to the beautiful colors it is supposed to have in the Fall, and the leaves are just crumbling off. It's hard to believe its just wind burn, but possible, I guess. Next Spring I'll move to a shadier spot, assuming it survives the Winter. I have 2 other japanese maples that are doing well, with much less sun, so perhaps that's the problem. We were told that this one is a very slow grower- is that the case?

How long have you had it? The symptom you describe sounds like leaf scorch which is due to insufficient water getting up to the leaves. Many factors can cause it, several of which have already been mentioned. It is also possible the root system is not healthy (overwatered?) or the tree is not well established. Full sun and a windy exposure will tax a weak root system.

I think we've had it for about 3 months. Perhaps it was not a well-grown plant to start, as when I received it, I noticed the curled-up leaves right away, called the nursery, and was told that it was normal- but it never really seemed to thrive. If the root system is not healthy, is there anything I can do to ameliorate now?

Thanks for your help