I'm a bit worried about one of our maples in the yard. I'm going to attempt to let the pictures do most of the talking as I don't know much about the tree itself. Last summer we noticed the limb go a bit dead. I always figured it was because my wife just hacked away a branch in some attempt of some mid summer shaping. Though looking at it, I'm worried that it might be a fungus? I see Verticillium come up a lot in my research. I appreciate the time folks.
Hi there-- Yes, this looks like classic vascular fungus disease, which I would say is still active, based on the spreading black bark. Don't give up, though. Remove all diseased branches promptly, cutting back to healthy green bark. Meticulous people sterilize their tools--I think you can use 10% Clorox in water--to avoid spreading the contamination from an infected cut to an uninfected branch. Areas that have access to good sun will resprout and fill in the space surprisingly quickly (a couple of years). My experience has been that most trees are capable of losing a branch or two, even large ones, and still recovering. Sometimes, though, you lose the entire tree and there's not much that you can do about it. Best of luck. There may be some solace in knowing that most Japanese maple growers experience this at some point. I wonder if, having evolved in relative isolation in Japan, this species didn't develop the broad resistance to fungal pathogens that continental species did. There are Japanese maples native to coastal China and Korea, I believe; I wonder if these are more resistant to disease. D.
Thanks for the explanation. It'll be a major branch for it to lose but the rest of the tree appears to be very hearty. So how does this fungus get onto the tree? We have some other maples that I want to make sure we do whatever to keep them healthy.
I'm eod's prune happy wife :) Thank you for your help! This morning I took the branch down to the trunk but still see a suspicious black outer ring moving down into the main trunk, I imagine from here it either heals or dies? Do they heal? Is there anything I can do to improve the "immune system"? More or less water, fertilizer? Also, should we apply something to the removed branch? I don't want to inhibit new growth and simultaneously don't want to create a huge open wound that further compromises the trees health. Thank you again!
Unfortunately the black ring moving into the main trunk is a bad sign, I fear the fate of your tree is with the gods, let us hope you are lucky. Does the bark look black on the main stem? If it is a relatively small area maybe you can remove it, as long as it doesn't girdle the tree. I doubt fungicides would help in this situation. (Maybe someone else knows better and can recommend a product). As for the pruning wound, it is best to leave it open to the air. As for water and fertilizer, too much is possibly worse than too little, moderate watering and use of fertilizer is plenty and waterlogging is to be avoided at all costs. Hope this is some help.
No obvious black bark on the trunk - If another limb starts to turn we'll have it removed... I'm hopeful we'll get lucky if not, how can we plant another tree there without setting it up for infection too?
