Continuing the discussion from Trident maple black spots:
Hey @bandi and @Ali10, I am new to Mirai and am glad I managed to find this post even though its been a while. I currently have a Trident and Japanese Maple struggling with the same issue as both your trees were a year ago. I was wondering if they are still healthy and what route was taken to correct the issue? I am pretty sure after a bunch of research that it is a fungal disease called “Anthracnose” which cannot be destroyed or cured, only managed.
@bandi, I see your technique gave you major success. Did you repot right before bud break/beginning of Spring? Did you bare -root all of the old infected soil? Did you spray Fungicide before or after the repot? What type of Fungicide did you guys use?
Spring started about a month ago out here where I am at in Santa Barbara, Ca. and both trees have pushed out a good flush for about a month before this issue started. I think it is too late for me to repot? Both trees are on week two of undergoing this stress and I just received a Fung-onil Bonide fungicide through Amazon that has “Chlorothalonil” as the basic ingredient to treat/manage Anthracnose on Maples. I also have Bonide Copper fungicide that has “copper soap” as the main ingredient to treat Anthracnose but it doesn’t list Maples as a species it treats and I read in a thread somewhere that “Copper Soap” is not good for Maple trees?
@Ali10, Did you end up pruning away infected foliage or did you start fungicide treatment with the diseased leaves in place? What was the outcome?
I’ve kept both trees in indirect sunlight, mostly shade because the leaves seem to burn easy. Drainage seems okay, however the Trident Maple is basically in a partially defoliated state from dropping leaves after they wilt up and die. The leaves that do remain on the tree are infected and some of the new growth already seems infected. The Japanese Maple is still young and in a growing pot and its leaves just started with black spots about a week ago.
I am just unsure how to go about the process, should I prune all the infected leaves and completely defoliate the tree, then spray the fungicide treatment? Or just start the treatment with the foliage it has now?
What do I do if the new foliage continues with the fungal diseases even after a few weeks of following the recommended bottle treatment.
Does this disease spread to other trees?