Fight plant fungus, black spot with homemade products
Using Homemade Plant Fungicide Sprays
Applying a homemade plant fungicide may kill plant disease and prevent its return. Spray the plant with the homemade fungicide in the morning before 10:00 a.m. or in the evening when the temperature is lower than 80 degrees Fahrenheit to avoid burning the leaves. Spray the top and underside of the leaves, repeating weekly if needed. Use a clean spray bottle.
Mildew: Use Milk and Water Plant Spray
Mix 1/4 cup milk with 2 cups water (or 1/2 cup milk with 4 cups of water). This weak milk and water solution will not harm neighboring plants. The milk enzymes help to control mildew on garden plants like cucumbers and tomatoes. In severe situations, increase the ratio of milk to water to 50/50. Either whole or skim milk can be used.
Leaf Spot and Mildew: Use Baking Soda and Water Plant Spray
Mix 1 teaspoon vegetable oil, 1 teaspoon baby shampoo, and 1/3 teaspoon baking soda in 2 cups of water. Before spraying the baking soda and water mixture, hose down the plant, hitting the top and bottom of leaves to help loosen and remove spores if present.
Root Rot: Corn Meal Sprinkled
Root rot of ornamental plants like azalea or impatiens may be controlled using corn meal, like the type you buy in the baking section at the grocery store. Sprinkle the corn meal on the soil under the plant and out to the drip line.
Help Prevent Plant Disease
Purchase disease resistant plants. Keep weeds under control. Water in mid-morning so the sun will evaporate water on leaves. Space plants apart for adequate air flow. If disease does attack plants, cut off the diseased area well into a healthy stem. Discard the disease cuttings and sterilize the cutters before using them again.