Black Spots on Leaves of Fuchsias
Fuchsias (Fuchsia spp.) are flowering shrubs from the evening primrose family and come in a wide range of sizes and flower colors. The deciduous or evergreen plants grow best in coastal growing zones and thrive in full or partial shade. Fuchsias are prone to numerous pest-related problems and diseases. A pathogenic infection causes dark spots to appear on the foliage.
Fuchsia foliage is susceptible to the fuchsia rust disease, a serious fungal infection caused by Pucciniastrum epilobii. Once infected, the entire plant is rapidly, often lethally, damaged by the fungus. Rust disease has many host plants including evergreen and deciduous trees and numerous flowering shrubs.
Rust on fuchsia foliage is characterized by the appearance of dark-colored or yellow spots on the upper sides of leaves with orange, dry or gelatinous masses of spores or fungal reproductive bodies on the undersides. The disease may be limited to just a few leaves in certain areas of the plant or may be spread throughout. Tissue swellings or galls are often seen on the foliage.
The growth on infected plants is seriously affected by the infection. Foliage and shoots are distorted, discolored and stunted. Most or all of the leaves may fall off. In cases of serious infection, younger plants may be killed entirely. Heavily infected plants are best destroyed to keep the disease from spreading.
Since the fungal spores persist in the fallen leaves, keeping the planting area free of debris is an important management strategy. Prune out and destroy all infected foliage and shoots at the first sign of damage. Using preventive fungicides helps to control rust infections. Minimize the use of overhead irrigation methods in landscapes as the prolonged presence of moisture on foliage favors the growth of fungus. Buy healthy transplants from reliable sources as the infection is frequently transported into the landscape with infected new plants. Make sure the fungicide being used is targeted to the correct organism as many commonly sold fungicides are not effective for the control of fuchsia rust.
- University of California Extension: Fuchsia
- “Fuchsias”; Edwin Goulding; 2002