I planted a Dappled Willow (nishiki) shrub 5 or 6 years ago. It has always done well and looked great until recently. The leaves seem to be browning from the outer edges inward. I haven't changed anything (i.e. same amount of water & fertilizer as in previous years). Any thoughts? It just so happens that my petunias, which reside about 10 feet away, have been invaded by caterpillar budworms. The symptoms are completely different but is there a chance they've invaded my Dappled Willow too? Any helpful suggestions would be greatly appreciated. THANKS!