Burning bush new foilage wilting
 

I have 3 burning bushes about 3 feet tall. Didn't notice this the
first 2 years, but this year....

The new growth on all 3 is turning over and wilting, even though the
mature leaves look perfectly healthy. In my opinion the plants have
had a reasonable amount of water....also I have numerous other
perennials; don't really see the problem on any of the other plants.

I can't think of what could be causing this on these 3 plants. Any
ideas?

thanks.