We have an azalea (variety Corsage, we think) that is falling victim to a wilt. The first symptoms we noted a few months ago. In the last two weeks the plant has taken a nose dive and is pretty much gone. My wife has surfed the net reading extension service pages and has arrived at a tentative diagnosis of Phytophthora. The azalea was well established and its near neighbors are other azaleas. Also, we have at least three other azaleas of the same variety elsewhere in the garden. The first question is, what precautions should we take to prevent the disease from spreading? How aggressive should we be? We would prefer to avoid synthetic pesticides, but would use them as a last resort to protect the other plants. Last summer, about ten meters away in a separate bed, we had a Carolina Allspice die of a rapid, progressive wilt. What's the chance that the same culprit is to blame?
Thanks, Ron. We just finished June with record rainfall, so yes it has been hot and wet. But the troubles of this plant started well before. Our suburban lot has been under careful cultivation for over forty years, most of that time owned by a professional gardener and only the last two years by us. The azalea in question must have been at least ten years old. I know the watering practices of the old owner (none except in extreme drought). We did the same. My dad used to tell a story. He was a physician, and one of his patients was a woman in her eighties with an arthritic knee. "I'm sorry," my dad said, "but you've worked hard all your life and you are getting up in years. Sometimes a knee just wears out." "I understand, doctor," she replied. "So why is my other knee OK?" I know some plants get root rot. I know there are a lot of variables. But I can't help wondering, why this azalea and not its neighbors? And is there anything I need to do to protect the other established plants?
