Question From: San Jose, California, United States
Q: we have a Japanese maple well established in a large pot. This year leaves have not appeared on approx. half of the branches and on inspection there are collections of yellow material around the junctions of the branches and where the leaf buds should be. Does anyone have an idea on what's causing this defoliation and what can be done? thank you in advance
A: Your tree may have Verticillium dahliae fungus, also know as Verticillium wilt. There is no cure. I would take a cutting of an infected branch to a nursery or garden center that specializes in Japanese Maples for a professional opinion. The check to see if the leafless branches are alive, using your finger nail or a small knife to scrape away a bit of the bark. There should be green beneath and cream color wood. If the wood is brown the branches have died. Japanese maples are very sensitive to drought. If your tree has been in the pot for a long time and not been root pruned it may be pot bound and sucking up water at a very fast rate. Take photos with you to the nursery. Best Nancy
