Hi Elizabeth –
Powdery mildew is the most common and widespread of fungal diseases attacking plants. There are several techniques for treating it without resorting to toxic chemicals. I’ve listed many of them here.
โข Stake plants to Improve air circulation
โขย Prune away leaves and stems as soon as you see signs of mildew. Make sure to disinfect pruning shears after each cut.
โข Use a thick layer of mulch to prevent disease spores from splashing onto leaves.
โข Keep leaves dry when watering. Drip irrigation and soaker hoses will help with this.
โข If powdery mildew is present, treat with a least-toxic organic fungicide. We often recommend Green Cure, Bi-Carb or Actinovate for the job.
Please see the following link for more information.
https://www.planetnatural.com/pest-problem-solver/plant-disease/powdery-mildew/
Good luck!
