Rhododendron root rot fungicide alternatives
Hello. When we moved in to our old farmhouse going on four years ago there were many beautiful big established rhododendrons, apparently magically immune to the deer, but this spring, almost overnight (or that's how it seems, it probably was over a few weeks) two of them are almost completley brown and shriveled. A friend suggested it was phytophthora (spelling?) or root rot, and after reading up on that, it does sadly look like that. Unfortunately we're going out of town, but is there anything I could drench the soil with NOW to stop further spread? There are many other rhododendrons, lucothoe, holly, etc. in this planting, I really do NOT want this to spread if there's anything at all I can do about it. Although it's been wet recently, we actually hadn't had that much rain in the last couple of months. I'm not sure why these big shrubs, blooming heavily last spring, would get this sick this fast. But anyway, any ideas on the best fungicide to use, or could I use hydrogen peroxide or bleach, diluted? Any ideas will be very welcome. Thank you.