Why are Leaves Turning Red on Plum Tree?
Rust and root rot are the most common reasons for plum leaves turning red. One cause of red plum leaves is rust, a fungal disease that results in bright yellow spots on the leaves with red spores on the undersides. It can be treated by spraying fungicide monthly leading up to harvest if the outbreak is early, or once after harvest if the outbreak comes later. Phytophthora root rot can manifest itself in discolored, sometimes red leaves. The red leaves may start on just one branch, then spread to the rest of the tree. The red leaves are accompanied by dark root crowns, sap oozing from the trunk, and brown spots on the bark. This problem is usually caused by improper drainage or overwatering. To fight it, dig up the topsoil around the tree to let the root crowns dry out.
More Plum Tree Problems Causing Red Leaves
Bacterial leaf spot is another possible cause of red plum tree leaves. It begins as black or brown spots on the underside of the leaves that eventually disintegrate, leaving a hole surrounded by a red ring. Prune your branches back for better air circulation. Apply fixed copper in the fall and spring. Coryneum blight can appear as small red spots on young leaves that eventually disintegrate, leaving behind a hole in the leaf. Spray with fungicide. Leaf curl twists and curls the leaves, coloring them red along the curled edges. The leaves eventually drop. Remove and destroy all the dead leaves and any other debris to keep the disease from spreading.