When powdery mildew attacks your begonias, the symptoms may be mild or severe. If you see light-colored growth begin on leaves and stems, take swift action to treat the powdery mildew before it advances to a more severe infestation that could damage your begonias. Get rid of mildew on begonias naturally using basic household ingredients. With concerted effort throughout the growing season, you can conquer powdery mildew and keep it at bay.
Fill the bucket with 1 gallon of warm water. Add the baking soda and the Murphy's Oil Soap and stir the ingredients well.
Pour the homemade fungicide into the spray bottle and screw the cap on tightly.
Cut off all affected leaves and blossoms with the pruning shears. Thin the plants by removing several stems to help air circulate more effectively throughout the begonia foliage.
Spray the natural fungicide spray onto the begonia plants at the first sign of powdery mildew. Cover the leaves, stems and blossoms thoroughly with the liquid.
Reapply the fungicide spray to the begonia plants once each week to control the powdery mildew and prevent it from spreading.
Keep the begonia plant properly watered. Do not overwater the begonias, but prevent undue stress from lack of water. Provide water for the begonias when the soil dries, watering until the soil is moist.