Do your leaves have the telltale texture and pallor of powdery mildew? Learning how to control powdery mildew is practically a rite of passage for most gardeners. So, if you think you're losing the battle and are reluctant to switch to chemical cures, here are a few all-natural treatments to discourage powdery mildew on plants.
Control Powdery Mildew with Chamomile
Chamomile tea is an easy-to-make, natural preventative and treatment for stopping powdery mildew on plants. To use chamomile tea to stop mildew spread, make a strong batch of tea (using about 5-6 tbsp of dried chamomile flowers for every 3 cups of water), cool it, then store it in a spray container. Spray on infected plants (including the undersides of leaves) but do not spray plants in direct sunlight (as this can damage the leaves of sensitive species). Mixture stores for 2-3 days.
Avoid Over-Fertilizing to Prevent Growth and Spread
An effortless way to control powdery mildew is to resist the urge to fertilize more than you need to. Nitrogen promotes growth, which means more of the tender, new flesh that's particularly susceptible to powdery mildew infection. Control growth and you help control mildew spread.
Use Baking Soda Spray to Control Powdery Mildew
Another easy-to-use, all-natural treatment for powdery mildew control, homemade baking soda spray is also effective against black spot. To make a baking soda garden spray, combine 1 1/2 tbsp baking soda and 1 tbsp vegetable oil together until the baking soda is dissolved. Then, combine the mixture with 1 1/2 gallons warm water, once again stirring until well blended. Pour into a spray bottle and spray on powder mildew on plants. Use immediately.
Try Neem Oil to Control and Prevent Infestation
A popular fungicide with all-natural gardeners, neem oil can be an effective tool for controlling powdery mildew. A neem oil spray applied to powdery mildew on plants works in two ways: it coats and protects leaves from future infestation and it smothers any powdery mildew that already exists. To make a neem oil spray, vigorously mix 2 tsp neem oil, 1 tsp natural soap (I like Dr. Bronner's peppermint soap — just be sure to choose one that does not contain sodium lauryl sulfate), and 9 cups warm water. Pour into a spray bottle and apply as needed. Mixture is good for 8 hours.
Thanks to geowillis, asifthebes and pirshulet for the images!