It was a combination of several thing, I think. First and foremost, I had moved from MA to GA in the summer fo '09'. Though the summers are hotter here in N. GA, they are more humid and my new back yard had less sun then in MA. The increased consistenly high summer temps seem to force some temperate trees into a dormancy state. Combine this with higher humidity and less the full sun, and these trees, being watered only once a day, were not drying out adequately. I also feel my soil mix of turface, lava, and grit, may not have had the best particle size, which contributed to the soil staying too wet.