Dwarf Japanese Maple Tree with leaves duding on only part of the tree.

Asked April 15, 2019, 6:55 PM EDT

I have a red draft Japanese Maple tree that the buds are just now forming leaves from the buds. But on approximately 50% of the branches, the buds remain tiny not growing and starting to open like the rest of the tree. Do you know why this might be occurring? There are some spots of white on the bark of tree, but they are on both the sprouting branches and non sprouting branches in relative equal amounts. I looked closely to see if this was Japanese Maple Scale, but don't see anything closely resembling the pictures I've seen of scale. Any advise you could give would be helpful.

Multnomah County Oregon japanese maples

1 Response

Thank you for your question. First, the pale green/grey growths you see on the trunk are not scale. They are not insects; they are lichen—a lifeform containing a fungus and an alga (plant). They are not the cause of the problem, but they often are an indication the tree is stressed or failing. Second, a failure to produce foliage is typical in a plant that is either diseased or dead/dying, at least in that part. This can occur if a tree has had a trauma such as a lawnmower, etc., cutting the bark. (I can’t see below the branch.) Third, this may be an early (or late) indication your tree is being killed one branch at a time by a soil borne fungus called verticillium wilt. You can read about it here: https://ipm.illinois.edu/diseases/rpds/1010.pdf Without cutting off a branch to look for the telltale browning, or conducting a soil test (http://plant-clinic.bpp.oregonstate.edu/), it is just a guess. You’ll need to decide how you want to proceed after reading all of this. Good luck!