Benign Leaf Galls on Young White Birch

Two leaf-stem-like growths on 4-5 ft white birch in Ontario. Owner asks cause and concern level.

Leaf Gall Explanation

Plant tissue induced by insect/ mite feeding or egg-laying in spring. Hormonal disruption creates protective structure around pest.

Key Facts

• Harmless to tree health.
• No control once formed.
• Fall off with leaves in autumn.
• Only problematic if covering most leaf surface (rare).
• Prevention nearly impossible.

Advice

Ignore them. Tree will shed galls naturally. No treatment needed or effective.