Arbutus leaf blight

Arbutus trees, iconic on Salt Spring Island, are susceptible to leaf blight caused by fungi like Elsinoë mattiroloanum and Ruptoseptoria unedonis. Symptoms include purple or brown spots on leaves, which may develop yellow centers or whitish areas as they grow. In severe cases, leaves fall prematurely, and twigs may die back. These fungi thrive in wet conditions, spreading via rain-splashed spores, particularly during the damp spring months.

arbutus-trees

To manage Arbutus leaf blight, start with cultural practices:

• Remove and destroy fallen leaves and infected branches to reduce fungal spread.

• Improve air circulation around the tree by pruning nearby vegetation and thinning the canopy if necessary.

• During dry periods, water deeply but avoid wetting the foliage.

• Applying mulch can help conserve soil moisture and promote healthy growth.

Chemical treatments like fungicides are generally NOT recommended for home gardeners due to limited effectiveness and environmental concerns.

Instead, focus on maintaining tree health through proper care, including fertilizing with a balanced mix to strengthen the tree’s natural defenses. If the disease persists or worsens, consulting a local arborist familiar with Salt Spring Island’s conditions may provide tailored solutions.