Some of you may remember that I purchased a Sango Kaku this past May. Everything was fine except for some leaf burn which I understand was expected on newly planted JM's that haven't been established. It has recently caught my attention, now that all the leaves have fallen, that a few of the branches have a faded colour in some sections. The faded colour is not at the tips but in the middle of the length of the branch. It is also only on one side of the branch (not the entire circumference). Is this something of concern? ie. the beginnings of diebacks or ,heavens forbid, verticillium. Or could it be something minor like sun scald? I've also included some night shots too. The faded colour is not very obvious, but it look cool nevertheless!
It will be interesting to hear what others think, but in my opinion it looks like damaged caused from constant rubbing over time. Sometimes it’s caused by a crossing branch or it may be from where the tree was placed at the nursery. Another tree could have been placed too closely or the tree was placed against something. Wind causes the branch to rub against the other branch or object overtime. Another cause could be from rope if the tree was tied during transport. I am not concerned about the health of the tree based on what I can see in the pictures.
Hmmm interesting. The branches of concerm aren't close to any other branches, so I don't think it's rubbing against other branches. Most of the faded areas are along the inside sides of the branch (ie facing the trunk), so I don't think it was ropes tying the branches during transport. Actually having said that, the fact that most of them are along the inside side of the branch means the fades areas are facing up towards the sky, suggesting it could be sun scald. So my question is could the sun have caused this fading to the branches? My JM does receive full sun during the summer. Also can someone dismiss the possibility that it could be the beginning of die-backs or verticillium?
In my 6 years’ experience growing Sango Kaku, I have never seen the sun cause that kind of damage. My tree gets about 70% available daily sun and the tree we planted for my parents gets 100% available daily sun in zone 5. I have never had a tree with Verticillium Wilt in my collection of 45 Japanese maples, so I am not a subject matter expert. It's my understanding it's not visible on the surface of the branch, but inside the sap wood. Usually a branch needs to be cut close to the trunk and it's visible in the cross section. Here is a link to an article on the subject: http://www.ct.gov/caes/lib/caes/doc...cillium_wilt_of_trees_and_shrubs_05-08-08.pdf and http://apps.rhs.org.uk/advicesearch/profile.aspx?PID=255
Hi, Doesn't look like any kind of verticillium to me. That usually shows up as darkish streaks moving down the twigs towards the main branches. This doesn't quite look like scald to me, sun or wind, but maybe more the latter. I do find that my sango kakus are unusually susceptible to twig dieback. The causes of this are poorly understood, but at least in part it may have to do with new wood that doesn't ripen sufficiently in our not particularly hot climate. Certainly newly planted trees (like yours) are more susceptible to dieback; the good news is it's not very serious in the long run if the plant can get established. To my eye it doesn't look like mechanical damage, but always very hard to say from photos. Is the tree getting some wind from the direction of the scarring? Good luck, -E
Good call Ron as Sango Kaku is highly susceptible. Good air circulation and good drainage can help prevent the problem. Be sure to be careful when spraying copper sulfate or copper hydroxide as some people have an allergy to it. Here is some info on the web about Pseudomonas syringae: http://www.hort.uconn.edu/ipm/nursery/htms/bblworn.htm Information specific to Japanese Maples http://japanesemaplediseases.blogspot.com/
That's interesting Ron. Another example of how different things are depending on area. In Normandie we don't really see much pseudomonas damage this early, we haven't really seen much frost yet. It tends to show much more in Feb and March, with successive freeze thaw cycles. cheers, -E
Hello squeez I also think that you can put the sun cause appart. Hi planted a Bhioo in this summer it is on a container in a north facing zone. I am also noticing lately this kind of of small faded colours in the branches with some dieback and black spots on the tips. regards
Thanks to everyone for all their replies. So I'm guessing the culprit here is Pseudomonas. It's been really busy for me lately so I haven't really gotten a chance to look it up. But from what I've read, Pseudomonas and diebacks sounds pretty similar. How are they different? And should I be concerned about Pseudomonas?
I've noticed this from time to time on a couple of maples though it doesn't seem to affect growth.Like Squeezled the affected areas usually seem to all face the same way so I think it initially has to be something external like sun or wind or even something nasty sprayed.However wether or not something enters the wounds and makes it worse after I don't know.I haven't had any cause for concern with it yet except asthetically.
Hey guys, I have a feeling my JM could have Tight Bark. Please have a look at the pictures again and advise on the issue. :/ FYI, this thread was how I came to find out about tight bark: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=8751
That was the first thing that came to my mind when I saw the photos. But I am no expert on the issue.
Anyone else with more thoughts? I understand that Tight Bark is almost at bad as verticillium wilt. I'm quite apprehensive that my maple has this. Am I to prune it off if indeed it really is tight bark? Any insight is much appreciated.
I hope someone with more knowledge can give the answer you are looking for, I'm really curious about your situation as well. I'm not knowledgable about it enough to give you advise, but I can tell you what I would do, unless I am advised otherwise. I would NOT prune it, and wait and see if it will heal itself and also observe the leaves on top. I would only prune it if it spreaded. Here we have some kind of a paste that is used for grafting and other types of wounds etc... to help them heal, so I would probably use that as well. I have no idea though that even if those problematic parts heal, whether they will retain the beautiful bark color of this particular cultivar. In the end, even if it heals it might not be appealing to the eye, so this is also an important factor about making a decision whether to prune it or not. I wish the best for your tree and hope that the problem is not a major one.
Yes, some of the branches on your tree are showing signs of Tight Bark. The nice thing to know is that this bacterium alone does not kill a Maple. But working in combination with another pathogen such as Verticillium alboatrum, after a stress or a series of stresses, can in time kill a Maple. The other nice thing going for you is that Tight Bark in cooler areas is not nearly as troublesome as it is in warmer climates. Thus, unless you see more signs of the topical lesions on the bark throughout this tree or see obvious signs of terminal tip dieback there is no real need yet to prune this tree way back to below the lesions. Even around here we would watch this tree for a year or two to monitor the spread of the topical lesions before we pruned it hard, a way back at the risk of pruning the tree in half. You are not there yet and as long as you can keep this tree growing in a semi or vigorous state there may not be a need to prune it at all. What you have to be mindful of is this tree ever stagnating in the ground for a year or longer. Then you may not have another viable option other of doing a hard prune in hopes to induce new growth to compensate for the older growth that was lost from pruning. For now just be conscious of how well this tree behaves in the ground but be aware that everywhere you see a lesion on the wood there will not be any new vegetative shoot buds arise from those areas. Jim
Thanks Kanuni and Mr. Shep! I really appreciate your responses. I'll definitely be keeping eye on my maple. I'm just relieve that my maple has a good chance of surviving.
