My young ( five year old ) red maple tree has small white blisters on the trunk and branches
Is my tree diseased? What can I do to save it? Also what is the best tree food or fertilizer for this tree and when should I apply it? The bumps just appeared last fall.
Certified GKH Gardening Expert
Without seeing images, my best guess may be Valsa cankers. These cankers will contain many small, white or grayish pimple-like bumps. This disease occurs when the fungal pathogen enters through injured bark caused by mechanical damage or pruning cuts. Valsa cankers also result in wilting and discoloration of the leaves, and branch dieback. Valsa cankers are most prevalent during periods of high humidity and rain, and trees that are unhealthy and stressed are more prone to valsa cankers. There is no cure for valsa cankers and control measures rely on cultural care. Provide enough water to the tree during periods of drought and ensure the roots have proper drainage. Immediately remove and destroy branches with cankers from the tree. Prune maple trees in the spring during dry conditions and disinfect pruning shears after each cut.