Birch trees, most often European White Birch and its varieties, including Cutleaf Weeping Birch. Paper birch is less susceptible.
- First stage Tree becomes stressed due to high temperature, low soil moisture or bark injury.
- Second stage The Bronze Birch Borer will attack the tree. A few leaves begin to wilt at the top of the tree, followed by a few twigs and then small branches. Finally a large branch or 2 will die. You can see the adult Bronze Birch Borers emerging from the tree in June from D-shaped holes.
The tree can only be saved if about 1/3 of the crown has been infected. If the infection has spread past this point, the entire tree should be cut down and the wood taken to the landfill.
- Avoid stressing the tree:
- Ensure it receives 2.5 cm of water per week.
- Apply mulch to the base of the tree to hold in soil moisture.
- Fertilize the tree every other spring with 20-8-8 fertilizer.
- Prune any dead or dying wood several feet below any visibly dead wood in August. Dispose of the wood at the landfill.
- Woodpeckers and some sapsuckers will eat the bronze birch borer.
- Not applicable.