HELP! Japanese maple yellowing leaves and dying
I planted a Japanese coral bark back in March in a half wine barrel container, and it was doing great up till recently. In May, we had an unusual heat wave of 100 degree for several days, the leaves are starting to yellow and wilting, even when I watered it pretty regularly. The tree was brought in a 15-gallon container, and root bound when we planted it.
More than half of the tree is yellowing :(
Close up of the dying leaves:
A few remaining leaves are starting to go too:
Is there anything I can do to save the tree? I hope it's not verticillium wilt.
Any help/hints is greatly appreciated!