Anthracnose Fungus on Loropetalum

Loropetalum

• For its outstanding performance in U.S. Department of Agriculture hardiness Zones 7 to 10, loropetalum won the 1997 Georgia Gold Medal Award in the shrub category. GeorgiaGoldMedal.org notes that loropetalum is native to China’s Hunan province and is a member of the Witchhazel plant family. Its pink or white flowers are identical in form to the yellow flowers of witchhazel shrubs but opposite in bloom season. Whereas loropetalum blooms spring through summer, witchhazel blooms fall through winter. As a broadleaf evergreen, loropetalum retains its leaves year-round and displays foliage colors including green, bronze, red and purple. Loropetalum is drought-resistant and does well in both partial and full sun environments.

Anthracnose Fungus

• Anthracnose fungus is a foliar disease that reproduces by spores and spreads by water splashing on foliage from rain and overhead irrigation. Tender, new growth is usually attacked first with fungal injury appearing as brown lesions on leaves. The dense form of loropetalum hinders leaves from drying thoroughly during periods of excessive rain, which accelerates fungal growth. The presence of anthracnose may be an indicator that plants are under stress, according to the University of Georgia College of Agricultural and Environmental Sciences.

Control

• Anthracnose control in deciduous plants is often self-correcting. After plants drop their leaves in winter, the new leaves appearing in spring do not exhibit fungal spots. However, in evergreen plants such as loropetalum, fungicides may be required to suppress perpetual fungal growth. Copper sprays, maneb and myclobutanil are recommended, but the University of Georgia cautions against using products that contain chlorothalonil as some cultivars may experience phytoxicity after chlorothalonil treatment.

Prevention

• Plants, especially older plants, may need renewal pruning, which requires the removal of dead, diseased and damaged branches. Stressed plants can be strengthened by cultural practices, including increasing soil fertility, ensuring adequate drainage and irrigating properly. Eliminating overhead irrigation, which wets foliage unnecessarily, minimizes a favorable environment for the growth of anthracnose. A soil test determines the need for fertilization by evaluating which nutrients may be needed for loropetalum to enjoy optimal vigor. Rake fallen leaves underneath shrubs diligently to remove diseased leaves that harbor anthracnose.