SORT AND FIND
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Gouty and horned oak galls are abnormal growths caused by a microscopic wasp that produces chemicals in the tree when depositing eggs. These chemicals activate a response in the tree which leads to the production of the galls. The galls are most often found on branch tips but may cover the entire canopy when severe.
Signs & Symptoms
- Large, round growths on the twigs
- “Horns” protruding from the galls
- Sparse canopy
- Canopy dieback in severe cases
Effects On Your Tree
Gouty and horned oak galls are most often found on pin and shingle oak. Their presence may indicate cultural issues in your landscape’s soil such as compaction,lack of moisture, or nutritional value.
Keeping your trees free of environmental stress is key to reducing gall infestation. There are chemical treatment options available that have promising results.