I have a nice 3yr Iijima sunago I picked up earlier this spring, and the other day I noticed some wilting leaves and what looked like the beginnings of some dieback at the tip of one of the branches - so, I pruned off the end to *hopefully* prevent it from spreading. But, after inspecting the tree today, I noticed that the branch had significant darkening lower down, which I had not seen when I pruned it, either because the leaves were blocking my view of that part of the branch, or because it wasn't there, I'm not sure. The rest of the tree looks healthy, though I haven't seen much new growth, and the rest of the branches and trunk appear to be fine. I am, however, still quite worried because this is exactly the same scenario that has occurred with several of my other trees this spring, and each on that it's happened to, I have lost - the blackening keeps spreading, no matter how much/little I prune off (I do sterilize my shears in between trees, and in between cuts on the same tree if I'm pruning potentially infected portions), eventually showing up either higher or lower on the trunk and by then all hope is lost. In early March, we did have a 5 day stretch where we had nearly constant rain and I did not move my trees under shelter during this time, so I think some of them may have been drowned out (they did not finally 'dry out' for nearly 2 weeks after), possibly causing the dieback and eventual death. Would this be a correct assessment? After the rain, many of the trees appeared to be suffering from either a fungus or pseudomonas, so I treated all maples with 2 rounds of phyton 27, which seemed to help most, though I still did lose several. Anyhow, are there any other thoughts as to what could be causing the dieback? How much should I worry? Should I trim the branch to below the blackened section, put cutpaste on the end (to seal it), and hope for the best? Any thoughts, suggestions, advice and/or precautions I should take with this tree (or my others) would be greatly appreciated - I really don't want to lose another tree!!
Hi Andrea, you need to cut to clean wood. The Phyton 27 was probably a good idea under the circumstances. -E
Well, I cut well past the lower dark band (halfway to the next set of leaves), put some cut paste on the end, and am keeping my fingers crossed. With my other trees, this is what I have done as well, but the die-back did not stop; any idea why that might have been or what I have been doing wrong when pruning? In either case, I'm hoping for the best this time around...
I don't use anything on cuts personally, could that be encouraging any potential infection to move downward rather than just drying out? Do you sterilize (diluted bleach or rubbing alcohol) your secateurs after each cut? I hope the best for you too, it would be a shame to lose this one now.
I don't know... Since I am a bonsai enthusiast too, cut paste is a frequently used item when pruning, especially on a larger branch; I guess it's certainly possible it's causing the infection to move down vs. simply drying out. I have started using Physan 20 as a disinfectant for my tools after reading about it recently. It has a lot of uses, so I thought I'd give it a try - would bleach or alcohol be better? But yes, I do sterilize in between cuts if I know I am working on an infected/possibly infected tree; if I'm just doing regular maintenance pruning, I typically only sterilize between trees.
I had hoped this issue was put to bed, but apparently not. After checking on my trees today, I noticed more blackening starting lower down on the same branch. Other than a spider mite infestation - most of my trees, maple and otherwise have mites to some degree; I have treated all with Bayer 3 in 1 in the last few days - and me not watering adequately during these hot days (hence, a lot of drying/dried/fallen leaves), the tree appears healthy otherwise. On one of the lowest branches, there are some new buds forming, there is no blackening anywhere else on the tree that I can see, so what could be going on??? Do I cut below the new section of blackening and hope for the best? Do I cut that branch off entirely? Do I leave it alone and see what happens? I would really appreciate some help with this, it has the makings of a nice tree and I don't want to lose it.
I'm also a bonsai enthusiast and I've lost many potted trees (not all of them trained for bonsai), especially maples last winter. I think that for most of them, the roots suffered and since the trees were weakened, they caught diseases that they could otherwise have be strong enough to fight off. Two years ago I managed to save two trees by cutting back low and applying copper sulphate before putting some cut paste. I didn't dilute it, I directly put the powder on the wound. I don't know if copper sulfate helped, but it surely didn't hurt. I also use aliette (Fosetyl-Al) before the trees leaf out or when I feel the root system might have some fungal problem.
As of today, the blackening covered almost the entire branch between the two nodes where it had started a few days ago. (The last two nights, we've had decent rain storms - don't know if this has played a roll in how fast whatever this is is spreading.) So, I cut off the branch halfway between the first and second nodes (above the split in the trunk) and put cut paste on it. Keeping my fingers crossed, but I'm not entirely hopeful... Regarding your use of copper sulfate: I don't have that, but I do have both horticultural oil, Bayer 3-in-1 for Diseases, Insects and Mites, Bayer Disease Control for Roses, Flowers and Shrubs, Phyton 27 and Physan 20. Would using any of these be beneficial? I did treat the Iijima earlier this week with the 3-in-1 as a drench due to a spider mite infestation I noticed on one of my other shrubs; would you recommend spraying the tree with this as well, or would one of the others be better? As a drench, spray or both? Thanks!!!
