Honeysuckle is an ornamental landscape plant likely to develop the fungal disease known as powdery mildew. Typically, powdery mildew will not kill a honeysuckle plant, and proper maintenance can help keep the plant free of fungus.
Several kinds of fungi contribute to the development of powdery mildew in plants. Each strain of fungi attacks only a specific plant. For example, the fungi causing powdery mildew on honeysuckle differs from that causing powdery mildew on azaleas, according to the Hoosier Gardener.
The most common symptom of powdery mildew infection is the development of a white, powder-like substance on the leaves of the honeysuckle. Severe infections will cause the entire leaf to turn white and eventually fall off.
Several environmental conditions contribute to the development of powdery mildew, including humidity, overcast conditions, and warm days and cool nights, according to the Purdue University website.
While there is no treatment that cures powdery mildew, planting honeysuckle in well-drained soil helps prevent its development, according to the Lady Bird Johnson Wildflower Center. Also, treat plants with fungicides to help protect healthy tissue. Space plants several feet apart in the landscape to encourage air circulation.