If residents notice the top centre branches of their birch trees browning by mid-summer then they should take immediate action. The problem may be a wood boring insect call the Bronze Birch Borer.  Populations of this borer are increasing due to previous years of drought and if left unchecked may be fatal to the tree. Bronze Birch Borers usually attack droughty, stressed or older birch trees. They can be detected by the presence of bore holes and conspicuous swellings of the bark in the upper most branches of the tree. If this borer is present in your tree the affected branches should be pruned out immediately.

It is important to understand that chemical treatments intended for the control of Birch Leafminer are not proven to be effective against Bronze Birch Borer. For more information on this pest, please visit this website: www.atl.cfs.nrcan.gc.ca/index-e/what-e/science-e/forestconditions-e/forestpestinfo-e/bronzeborer-e.html

       Bronze Birch Borer is killing Birch tree                       Beetle exit hole

The other major reason the upper centre of a birch tree may start to wilt and turn brown is because of summer drought. Birch trees prefer a cool moist growing environment and require more water than most other landscape tree species, especially when growing in a lawn. Often the first inch of precipitation or irrigation that week is utilized by the lawn grass before it can reach the tree roots. A good tip is to use a slow trickling garden hose left over the trees root zone for a few hours. This ensures that the water reaches the trees roots while minimizing run-off and evaporation.

Several other species of insects like the birch leaf miners and skeletonizers feed on birch tree foliage; however the resulting brown leaves occur throughout the tree and are not localized to the top of the tree as first occurs with Bronze Birch Borer feeding.

Media enquiries may be directed to:

Jim Donnelly, Integrated Pest Management

Parks Department

City of Grande Prairie

Phone:  780-513-5226 

Fax:      780-532-7588