Japanese Maple sudden damage
I have a 10 year old Japanese Maple that has been moved to larger and larger containers over the years. It is currently in a large wine barrel where I moved it about two years ago. It has always been healthy and happy. This spring it leafed out beautiful and full. Then suddenly, it seems like over nite, the upper and outer two thirds of the leaves turned brown and curled up as if I had not watered it. We've had very wierd weather here in the SF bay area, and I don't know if it's due to the weather. I'm afraid it's dying...and I'm very attached to it. Help?