Vinca minor, also referred to as common periwinkle, is a ground cover that is susceptible to a variety of fungal diseases. From cosmetic damage to severe injury of major plant components, disease can destroy your plants. Identify proper care, types of diseases and their symptoms as well as appropriate control methods to keep your common periwinkle healthy in the home garden.
Proper care of vinca minor results in healthy, vigorous plants that are more likely to resist or are able to heal from disease when compared to stressed or weakened plants. Grow vinca minor in well-shaded conditions, particularly in the summer, to avoid damaging sunlight, according to the University of Arkansas Cooperative Extension Service. Plant in well-drained soil that is rich in humus, and avoid excessively wet sites and waterlogged soil.
Vinca minor is often affected by fungal infections. Root and stem rot is caused by the fungus Rhizoctonia solani; this fungus lives in soil and generally attacks weakened plants before it attacks healthy ones, according to the University of Arkansas Cooperative Extension Service. Another fungal problem is stem blight, caused by the fungus Phoma exigua var. exigua. This fungus lives in fallen plant parts and soil, attacking during periods of extreme moisture and cooler temperatures, according to the University of Illinois Extension IPM.
Symptoms and Damage
Root and stem rot of vinca minor displays symptoms of wilted plant parts before other symptoms arise. Dark-colored lesions appear on the stems close to the soil line in either dark brown or black hues, according to the University of Arkansas Cooperative Extension Service. Root systems, as well, become dark in color. Darkened areas are dying plant tissue. Fungi spread easily from one plant to the next, causing expansive areas of infected vinca minor. Stem blight is similar to root and stem rot as its symptoms include darkened lesions. Lesions quickly cover the stem after wilting occurs, and the plant dies as the fungi spread to the leaves.
For these fungal diseases of vinca minor, avoid extreme shade and wet conditions to prevent the proliferation of fungi, according to the University of Arkansas Cooperative Extension Service. Remove and destroy infected plant parts to help ailing plants and to prevent the spread of disease. When using pruning tools, sanitize the blades between each cut and from one plant to the next to further inhibit disease transfer.
Though chemical control is not recommended for stem blight, root and stem rot of vinca minor are treatable with fungicidal application. In combination with cultural control, apply a fungicide with the active ingredient propiconazole, myclobutanil or other active ingredients labeled for use on vinca minor for root and stem rot, according to the University of Arkansas Cooperative Extension Service. Apply to the entire plant as a preventive measure or the moment you notice symptoms.