Yucca Cane Diseases

Symptoms

• Southern blight (Sclerotium rolfsii) is a fungal pathogen that inflicts all parts of the yucca, although it is most common on the stems, especially at the base. Initial symptoms include cottony white dots, the size of a mustard seed, on various parts of the plant. Look for a white fan-like fungal growth on the soil around the yucca’s cane. Another fungal pathogen, Fusarium, causes soft rot of the stems and eventually travels to the plant’s foliage. The infected yucca wilts and dies rapidly. Inspect the ailing yucca for round, red fruiting bodies and clusters of gold or yellow-brown powdery spores.

Control

• Fusarium stem rot on yucca has no known chemical control, so your best option to keep the disease from spreading is to remove and destroy the plant. To control Southern blight, the specialists at the University of Tennessee Extension recommend applying a fungicide containing flutolanil at the first sign of the disease. Read the label completely to determine application rate and to understand cautionary statements.

Prevention

• Don’t plant anything in soil in which a Southern blight inflicted yucca has grown. Even removal of the top few inches of soil doesn’t get rid of the pathogen, according to nursery specialists and plant pathologists at the University of Tennessee Extension. Keep the yucca planting area free of weeds to increase air circulation around the plant. For added protection, apply flutolanil fungicide during the first week of June. Direct the spray to the lower stem and roots at the rate listed on the product’s label.

Considerations

• Learning about the proper way to plant and grow the yucca helps avoid some common diseases and other problems. Yucca plants thrive in sandy or rocky soil. This type of soil is the antithesis to that sought by the fungal pathogens that attack its stems. Cool, damp soil causes rot. If you have organically rich soil, grow the yucca on a mound or in a raised bed in sandy soil. Don’t fertilize the yucca and water it only during extended periods of drought.