Help! My delphiniums (which are in pots) have a problem. It looks like powdery mildew, or mold, its greyish and powdery with some black areas. Its mostly up the stems but is also affecting the flowers. I had two delphiniums from last year come up nicely in the spring and now one hasn't even flowered. They both have new growth at the bottom (the one with flowers has more) and I have been cutting back the infected parts. I also bought a new delphinium the other day and its already spread to that plant as well. It seems to be affecting the flowers. Does anyone have any ideas? I have been googling around but haven't found anything that looks similar. So far it has not affected any other of my plants. Thanks so much!
