Hi. I need some help. I believe my acers are all dying and it's very sad. I have had some of them for over 10 years. Is there anything you think I can do? Please any help will be much appreciated. It's a collection I started loooong time ago and I love them so much.
To be honest, they don't look as if they could survive. If it's phytophtora or the like, some have a slight chance to survive if you use a copper-based fungicide. If it's verticillium, they're goners. Sorry...
Thank you so much for your reply. I will buy the fungicide and I will get rid of the most damaged ones. Hopefully some will survive. Thanks a lot for your reply
Basically, verticillium goes from the top of the branches down : very bad. Some of your trees seem to have dark spots lower down, maybe they can be saved. If the lower part of the tree is OK, prune the rest hard, and "paint" the cuts with smthg like bordeaux mix. I saved some this way...
I agree with Alain in all respects - In all the years I have collected JM, I never seen so many JM suffer like this simultaneously, I wonder if there was an issue with the soil..once you have done what you can to save them, if they die I’d dispose of them and the soil thoroughly and use a suitable anti bacterial product on any retained pots. Sincerely sorry to read this post, devastating.
Not exactly. Verticillium is a soil-borne disease. Classically it invades the roots and works by invading the xylem/wood (so it proceeds upwards, @AlainK). It can be introduced via bark damage low enough for water/rain splash to infect or via a contaminated cutting tool. Verticillium is most active in the cool of spring. The classic symptom is that all the leaves on a branch/branches/the tree suddenly wither (again, in spring). About the only way it can be introduced in an urban environment is using some contaminated soil. Normal composting does kill verticillium. I rule out verticillium just because @Dulce is asking now, not it in the springtime. This is, though, a time of year associated with Pseudomonas syringae other bacterial infections. At any rate, the blackened areas indicate death of the cambium. The flow of stuff in the cambium is downward, so it progresses downward and can be removed by pruning below the blackened area - then apply bordeaux mix or spray a copper-based fungicide as @AlainK advises, as it will also kill most kinds of bacteria. . If so, it would indicate the organic soil has broken down to the point that the roots have not been getting sufficient air (oxygen) to survive. Possibly they are drowning, given that the rainy times have returned. You might knock the pot off one and see how dense/wet the soil is on at least one of them, @Dulce. just to see if there is any direct evidence to support this. Further, if you find dense-wet soil, think about repotting it by washing away all the soil and spraying the roots with fungicide before repotting it in fresh composted soil. Maybe try it also on another so that by next spring you can assess whether repotting and disinfecting or just spraying / pruning+bordeaux is effective or not. However, given the preponderance of blackened bark at ground level, I'm not optimistic that anything can be saved. Regardless, I think spraying all your other trees with a copper based fungicide is a good idea. Sprays are only effective as a prophylactic. Once the pathogens are inside the tissues it is near impossible cure with anything other than a systemic (hence why pruning the infected tissue is SOP).
Thank you so much for all the information. I was also thinking about reporting them to try to save them. And yes to use the fungicide at the same time. I have been reading about how to check if it's verticillium by observing green, brown marks inside the infected branches? I will do that tomorrow after work. It's only the coral bark one that got black spots in upper branches.... The rest of them it's just on the bottom of the trunk ... I know it's my fault as I have neglected them and I have only watched and enjoyed their colours... I haven't changed the soil for a while and I'm sure the roots are dying. I will also check the roots tomorrow. I have been reading on the forum to find the best growing medium to report them this weekend. To be honest I feel hopeless at the moment...And then I remember doing so many things to take care of them in the past... I appreciate a lot your answers. Thank you
