|I planted a pee gee tree hydrangea last spring- was doing well. Leaves started to yellow, & brown, curl a little last week . Tree is starting to bloom. The wood is green when scraped,no trauma to any part of tree . It gets filtered sun, a couple hours of sun, then shade. Cedar shredded mulch( I've now removed it)at base of tree. Other perennials around the general area doing fine. I took a soil sample from beneath the tree to Burpee Gardens in Downers Grove to be annalized. They didn't think it was rust. Just in case I sprayed a fungicide. It's been Fertilized with miracid 3 times since planted. The yellowing, browning is getting worse- leaves are starting to drop off today.
|Based on your description of the problem, I would suspect several possible scenarios. The symptoms you describe sound very much like moisture stress which would be exacerbated by the plant trying to bloom. Under watering could cause the browning and defoliation, but so could over watering. The soil should be evenly moist but not soggy sopping wet. Mulch would help to keep it cool and moist and is usually a good idea. The plant may show some chlorosis in alkaline soil, so you might want to check the soil pH and adjust that gradually if needed.If this is the problem, a water soluble fertilizer for acid loving plants can be used as a temporary measure, as may a supplement containing chelated iron. There is also a possibility that it is suffering from a bacterial or root rot problem. Your county extension (737-1178) should be able to help with the soil testing and interpreting the results as well as diagnosing the cause of the problem.