Japanese Blood Maple - Ask Extension
I have a 20-foot Japanese Blood Maple in my yard bed. I discovered last year that one of the branches was leafless, except for close to the trunk. T...
Knowledgebase
Japanese Blood Maple #125249
Asked May 04, 2013, 11:43 AM EDT
I have a 20-foot Japanese Blood Maple in my yard bed. I discovered last year that one of the branches was leafless, except for close to the trunk. This Spring, I have several leafless branches. Do you have a regimen for determining if it is diseased or infected by an insect?
Marion County Oregon
Expert Response
Hi:
This sounds a lot like Verticillium Wilt, unfortunately. I've attached a link to the PNW Disease Management Handbook entry on this disease. Feel free to contact me for more information.
http://pnwhandbooks.org/plantdisease/maple-acer-sp-verticillium-wilt
This sounds a lot like Verticillium Wilt, unfortunately. I've attached a link to the PNW Disease Management Handbook entry on this disease. Feel free to contact me for more information.
http://pnwhandbooks.org/plantdisease/maple-acer-sp-verticillium-wilt
Hi Neil, thank you for your help! I sprayed the tree and drip line with copper sulfate 50%. Larger affected branches have sparse leaf growth on tips and normal leaf growth nesr the trunk.
Should I remove all affected branches at the the trunk or above the healthy leaf growth near the trunk? Or is the tree not likely to improve? Should I continue spraying with copper sulfate for a couple more applications within a month period?
HI:
If in fact it is Verticillium the copper will not help. Copper can protect the plant from foliar diseases but Verticillium affects the water-conducting tissues inside the plant. I would remove the branches above healthy growth I suppose and clean the snippers or saw between cuts thoroughly with a 10% bleach solution or 70% alcohol. Japanese Maple affected by Verticillium wilt tend to decline branch by branch over a number of years. Eventually they become so sparse that they lose most of their ornamental appeal. Like other vascular diseases, this one has no cure, I'm afraid.
If in fact it is Verticillium the copper will not help. Copper can protect the plant from foliar diseases but Verticillium affects the water-conducting tissues inside the plant. I would remove the branches above healthy growth I suppose and clean the snippers or saw between cuts thoroughly with a 10% bleach solution or 70% alcohol. Japanese Maple affected by Verticillium wilt tend to decline branch by branch over a number of years. Eventually they become so sparse that they lose most of their ornamental appeal. Like other vascular diseases, this one has no cure, I'm afraid.
