Willow Leaf Galls: Identifying and Managing Gall Insect Infestations

What Are Willow Galls?

Galls are abnormal growths caused by tiny insects (usually sawflies or midges) laying eggs in leaf tissue. The plant forms a protective structure around the larva. One side of the leaf may show a raised bump; the other appears sunken.

Management

• Galls rarely kill the tree; they're mostly cosmetic.
• Rake and destroy fallen leaves to reduce next year's population.
• Chemical control is usually unnecessary; natural predators often keep numbers in check.

Resources

For more details, see Willow Gall Insects.