What’s wrong with my River Birch?

Question:

River BirchI bought this River Birch ‘Fox Valley Dwarf’ about three years ago. I lost the second and third stem the first winter but the now-single stem has done okay since then, it’s currently about 5′ tall. But it has these galls or something every year. It doesn’t seem to be hurting the tree too much, but this year they were worse than ever, like every single leaf was covered.

Is there anything I can do to treat it? Will it always be this way? I’m sad because it’s my son River’s tree, we planted it when he was a baby and it looks awful now.

Answer:

Lynne M. Holland, Horticulture and Social Media Professional

Please see the response below.

“In response to your question on the River Birch “Fox Valley Dwarf” our entomologist has diagnosed the problem to be mites. They are not caused by the aphid you thought, but by a type of mite (probably eriophyid mites) that causes galls on River Birch called “Taphrina galls.”  The following link has more information, Taphrina gall on River Birch? #659963.

Feel free to contact Lynne Holland if you have any other questions or concerns.”