Trees are susceptible to a variety of different pathogens like blight, rust, scab, leaf spot, black spot and mildews. Fungal spores spread easily from splashing water, insects, animals and garden debris. Trees that are already stressed due to improper growing conditions or insects are the most susceptible to pathogens. Fungicides work to stop the disease from spreading and, in some cases, prevent the disease from occurring. Make effective, homemade fungicides using ingredients common household ingredients.
Apple Cider Vinegar
Black spot, leaf spot, scab, mildews and other diseases are killed by apple cider vinegar solutions. Use apple cider vinegar that contain 5 percent acidity, and mix 3 tbsp. in 1 gallon of water. A dash of molasses or mild dish soap helps the solution cling to the tree longer. Spray the tree either early in the morning or evening to avoid direct sunlight.
Garlic is chock full of antibacterial and anti-fungal properties like allicin and sulfur that work against pathogens like powdery mildew, downy mildew and leaf spot. Make a fungicide solution by infusing 3 ounces of minced garlic in 1 ounce of mineral oil for at least 24 hours. Mix with a gallon of water and a dash of mild soap. Mix the solution thoroughly and continuously throughout application. Spray the tree including the undersides of the leaves. Don't apply in direct sunlight.
Use horticultural cornmeal or whole cornmeal to kill soil-born diseases. It works by stimulating beneficial microorganisms living in the soil and encouraging them to feed on the pathogens. Use 2 pounds per 100 square feet. Spread the dry cornmeal on the soil around the base of the tree and spray with water to activate. A foliar spray is made by soaking 1 cup in a gallon of water. allow it to soak overnight, then strain and use the remaining liquid to spray the leaves.
Bicarbonate, or baking soda, has fungicidal properties when mixed into a liquid spray. It acts as a protectant from many fungal diseases and kills some organisms of already infected plants. Baking soda is effective against a wide range of diseases including powdery mildew, blight, anthracnose, Botrytis, downey mildew, Fusarium wilt, rust and scab. Dissolve 1 tsp. of baking soda in 1 quart of warm water and add a small dash of mild dish soap to help the solution stick the leaves. Spray infected trees thoroughly out of direct sunlight. Prepare the solution carefully and precisely because if it too strong it will burn the tree.