Will Your Homemade Spray on Solution Using H. Peroxide Work on Hydrangeas
Potted hydrangeas have mildew. Had to move them to the shade in my patio due to fierce sun and heat.
Certified GKH Gardening Expert
Yes, they should work fine on hydrangeas. The powdery mildew can also be treated effectively with neem oil. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm