I planted a row of 6-foot emerald green arborvitae (thuja occidentalis 'smaragd') in my back yard about four months ago (May 2005), and have been careful about regular watering since then. After a one-week vacation, I returned to my home to find one of the trees with totally yellowed and brown foliage (no remaining green). The other trees (immediately adjacent-- presumably with the same environmental conditions) show slight signs of yellowing, but are on the whole faring much better than the tree in question.
I'm located in Brooklyn, New York (zone 7), which has had a hotter than average summer, with very little rain-- I would say drought conditions.
Should I assume that the tree is just suffering heat stress and is dormant and will recover, or should I assume the worst and simply buy a new tree?
Thanks in advance!
Mark