Powdery Mildew

Powdery mildew is an opportunistic disease and can be exacerbated by too much shade. Good air flow helps prevent it—in other words, plant where there’s a bit of a prevailing breeze when you can and prune for good air circulation within the plant. Depending on what your plant is you can use Daconil which is a synthetic fungicide or Serenade, an organic fungicide. You will have to read the label to see if your plant is listed to be treated with the fungicide. Make sure you clean up all the leaves underneath the plant and put in the garbage, not the compost. You should start treating immediately. You will have to treat again next year because the spores will winter over in the soil. Without a doubt, this is one of the worst cases of powdery mildew I’ve ever seen.