Anthracnose, also known as leaf blight, is one of the most common garden diseases commonly found in the eastern U.S. Multiple plant species are susceptible to anthracnose, which is caused by a fungus. Dark lesions form on leaves, stems and even fruits. After the dark spot forms, the center of the spot turns a faded pink color, followed by leaf, stem or fruit rot.
Choose plants resistant to anthracnose, such as Modesto ash trees, sycamores and evergreens. Plants grown or seeded in the western portion of the U.S., usually are not exposed to the disease. Ask your local nursery or garden center experts to suggest native plants to your geographical area that may be resistant to the disease.
Avoid spreading the disease from one infected plant to another by disinfecting garden tools using about 1 part bleach to 4 parts water when moving from one area of a garden to another, especially in the case where anthracnose may be suspected. To be on the safe side, dig up and dispose of the infected plant. Don't use the infected or dead leaves, stems or fruit as compost or mulch, as the disease spreads rapidly through such debris.
Plant your shrubs, flowers or trees with room for leaves and branches to dry after rains or snow without crowding. This helps prevent the fungus from growing in consistently wet and shaded areas. Maximize air circulation between shrubs and trees and rake and dispose of all leaf droppings, branches and debris regularly.
Apply a sulfur or copper powder or spray to infected plants when you first notice signs of spots appearing on a leaf. If you're not sure, take a sample leaf to your local nursery to confirm. The sulfur or copper spray or powder should be applied to the affected plant on a weekly basis throughout the growing season. While these powders or sprays will not kill the disease, it will prevent it from spreading to other plants through seed germination.