I thought I would start a thread to help us address some of the bark-related issues seen frequently in Japanese Maples. Hopefully this will encompass sunburn, canker, fungal, bacterial and other unexplained issues like splitting and dieback. While we often see more than one problem present at a time, there is usually some underlying issue at the beginning. What I have in this series are three trees from a friends yard photos taken today 7/31/05 and one of my trees, Acer palmatum 'Green Mist', photo taken last fall. The first tree is is a red dissectum, labeled as 'Red Select' that is in the ground and appears to by ten years or better in age. The tree suffers regular dieback and showed some decay on the primary branch in the crown this past spring. I did some heavy pruning for my friend and we started a fertilizer program to increase vigor but I suspect we are up against some Verticillium and some widespread calousing in the bark. The second and third photos are of a palmatum labled as 'Aka shigitatsu sawa' (not the true form) that is probably 7 years or better in age. You can see a similar bark issue on this tree and the dried leaves happened nearly overnight after about the 8th or 9th day here over 100 degrees. I saw the tree a few weeks back and it looked terrific. I can already see some twig dieback occurring and I think it will be heavy pruning and fertilizer again to try to sustain the tree. Fourth is an Acer japonicum 'Green Cascade' about 3years old and the fifth is Acer Palmatum 'Green Mist' (that photo taken last fall) about 4 years old. Here again we see the same bark callousing and even a little splitting on the new chute of the 'Green Cascade'. The split is not as worrisome as the bronze coloration around the spot that makes me suspect a short life for this little branch. In the Green Cascade, this is the early stages of what will likely become quite widespread in the years to come. Both of these trees are currently in excellent health if we evaluate the foliage. Happy viewing! MJH
Hi, Good post! When you refer to 'fertilizer program' to deal with these bark related issues, what exactly would you suggest? Thanks in advance! G
Hi G, By fertilizer program I mean offering the tree a complete complement of macro, micro, and trace nutrients, especially salt forms that offer Calcium to our tree. The problem with the callousing, whether sunburn caused or bacterial or fungal, is that no new growth can emerge from that area. When the branch tries to expand during growth, it will be either entirely consticted or we can see some splitting. While the branch will remain alive, it will not grow much or any in calliper. We will also not likely see any new budding from that wood. If we let the symptoms persisit outward on the branch or let the tree stagnate or become stressed we risk losing the tree if we lose the good foliage. Or, we may lose a branch or two. It is very similar to the way verticillium constricts or blocks water and nutrient flow. My feeling is that in a landscape tree, or one planted in the ground, within "X" number of years it will deplete, to a large degree, the nurtrients in the soil. Or mabye a better way to think of it would be a decrease in nutrient density especially when planted in a garden or with other heavily feeding plants around. I usually will allow a many as 5 years or so to pass before adding anything other than 0-10-10 in the fall. I do this from year one. A tree in the condition of yours and the ones I show above will not be able to support vigorous growth and we do not what to push this growth. Use a fertilizer with a nitrogen mix of soluble nitorgen and insoluble and that has good balance of Phosphate and Potash (PK) with calcium in the salt. I do not have a fertilizer I am using on landscape trees, but in the past I have used Sta-green slow release grannules before we moved and let all the in-ground trees behind. Now I have all potted trees and treat them differently. Jim recommened this product in another thread: We cannot get the Bandidi products around here, but you see the ratio that you will want to work with for late spring/summer applications. In doing this you will sustain vigor but not too much nitrogen-induced growth. Also, but careful in pruning. It will be good to pinch back any long new chutes, but don't prune back into the calloused wood as you risk no new growth emerging. I hope others offer some opinions as we often don't talk much about sustaining vigor in our plants under different physiological conditions or to achieve an particular result. There was a fertilizer thread started but without a particular purpose in mind, it was hard to really say what works best. For example it appears that regular application of low concentration water soluble products works very well for potted plants when they are young and then we we get them up in size to 7gal or better we can start using the slow release grannules. Different techniques at different ages and under different conditions. Hope that helps. Michael
This extremely important thread, the most far reaching in importance, most pertinent offering to date up for discussion in this forum, shows a condition that will affect all of you in some way that have Maples. If you only knew just how prevalent this disease is you would not dare "run" from it. What we can see enough of going on in these photos, by itself, is the second most destructive disease of all Japanese Maples. In conjunction with a form of Verticillium this pathogen has killed more Maples over time than the quick decline form of Verticillium has. We called it in the nursery amongst ourselves and with only a couple of people here and in Japan, Tight Bark. I've now done what would be expected of me. Now you guys can deal with this subject amongst yourselves. The subject herein is the one that all of you need to pool your resources together to work on and learn to guard against. Even today there is no preventative for this condition other than to select wood from parents that do not show the symptoms and even then there is no guarantee the offspring will not get it over time. This disease can be and is passed from the parent to the offspring, even from seed. Other than quick decline Verticillium this "slow death" is your worst nightmare in Palmatum, Japonicum , Shirasawanum, Sieboldianum and some of the Circinatum forms I have been around. Luckily, so far, Buergerianum seems to be immune to it. Jim
Michael, Here are some questions for you and others who have viewed the photos and have similar symptoms: How many of these plants are in an exposed sunny location? Are these symptoms more prevalent when the tree is in sunny or shady conditions. Does the grey scarring occur only on the top (sun) side of the branches? What happens if a tree that has these symptoms is moved to a shade area for a few years? Do these symptoms occur mostly on older trees (4 yrs +)? Do certain trees or types of tree tend to have the symptoms more often than others? For example do red leaf forms or lace leaf forms exibit the symptoms more than green leafs? Seiryu does not seem to exibit these problems as much as other forms. How come? Is this occuring more in certain parts of the world? Australia...whats happening down under? robert
I am greatful that Jim kickstarted this thread. I have had some knowledge of this condition for a short time, but remember that my short time in plants has not given me a great depth of experience with larger plants to see how this condition might progress. I have a large number of small plants, some up to 10gal now but mostly 3-5gal and under 5 years old. My experience will come in watching these plants grow and in my searching for new plants. With that said, I will try to give you my thoughts. No. The scarring our calousing can occur anywhere on the plant. I have a Yezo nishiki that has scarring on the lower trunk right above the graft union. I recenly bought the Green Mist photographed above from under shade cloth where it spent most of its life. I do think that direct hot sun plays a role in the presentation of the conditon. The role of sun I suspect is related to the bark temperature (I am way out on a limb here) and how the bark would expand and cool at a greater rate in direct sun opposed to shade. I think this is why be see small splitting in the tight bark areas that receive direct sun as seen with the Green Cascade above. Direct sun also causes more stress for the plant in more temperate climates like we hear about here in Oregon and California and in areas of the midwest and southeast. Where you are in Mendocino the sun, or mabye it is the overall heat intensity, is not as great. Once we can see the visible signs of tight bark, they do not go away or reverse or diminish. The plants I have, either stay about the same or get worse. In shade we benefit from less stress on the tree and that we can prolong the "good days". I have not observed for multiple years, but there seems to be no way from the tree to heal itself so I can't see how we could assume that the presentation would ever diminish after we have seen it. What greatly separates tigth bark from other bark-related injuries is that usually we see the maple COMPARTMENTALIZE the damage area form a scar around it and the cambium then builds up or grows around the area to circumvent the inury. This does not happen with tight bark. Even a small calloused area can mean injury and constricion to the entire branch or twig. The whole area seems to be effected even if the symptoms are not visible on the entire branch or twig. Once we agree that future growth is greatly compromised on any branches with tight bark we see that our options are few to treat it and the best treatment may be a preventative of keeping a healthy plant free of stress and then being vigilant about monitoring for tight bark and pruning out what we can when we see it. It seems to develop over time, so older trees are the better place to find it. But as you can see the Green Cascase above is only two years old. If the scion would used already has visible symptoms we can see it right away. I suspect that infected rootstock will also transfer the condition to the grafted variety and then it will take time to develop. Also, older trees have had more opportunities to encounter stress and thereby might develop outward symptoms. But, in buying plants, it would be helpful to buy from a grower that grafts his own plants and be able see the stock plant that will be of age to show the condition. This is a huge issue with the way scion wood moves from place to place sans stock plant. The other option is then to buy the oldest plant possible to monitor for the condition. There is one grower I used to buy a great deal from. They are mostly mail order and seemed to have a large excess of larger trees that had become to big and too expensive for the mail order market. They had so many accumulating on the "back 40" per se that I wondered why they didn't sell to local nurseries or do a fire sale of some sort. Anyway, I would go there and stroll through the larger plants looking for the right one as they were small landscape size. I felt these trees were not really well cared for or pruned and I don't think they were sources for scion wood. All at least 3-4 years old, they were laden with tight bark and verticillium. This is how I first became concerned about what might happen to my small liners from the as they got older. This is one thing I am not certain of. I have seen it on quite a number of veriegates and many dissectums, especially red ones. Any of the atropurpureums seem to be effected. I can't say for certain about Seiryu, but we might be able to make some connection between vigor, health and tight bark. I think everyone will admit that there are come maples that are better growers and stonger plants. Seiryu is certainly one of these. Other plants seemingly always struggle, are subject to regular dieback, fungal dieases like mildew, and will always challenge us. In the end, when we start to separate out the clean from the dirty maples, we might see a pattern of verticillium and tight bark distribution, but I cannot say for certain. I will go search my collection and see what I can dig up for more photos. While this is the ideal thread in a forum like this, it sort of changes the face of things if people are to admit that this problem exists. The practice of buying plants sight unseen takes on a whole new risk. Then again, many people never imagine having their plants for 15 years. That is a good thing as once we start losing branches to tight bark and verticillium, we won't have our trees that long anyway. MJH
Hello MJH, I was reading your original post and can't find the photos that are supposed to be attached to it. Is it my browser or did you remove them for some reason. I'm very curious to see them as I have a green Japanese maple whose bark looks as though it's been sandblasted, scraped off, scarred, and greedily gnawed on, and want to see if it resembles anything that you are discussing. Thank you. ^_^ n. musume
Hi, I remember you posting the pictures and was hoping of a big response within the group. What I know so far is that there is no cure for tight bark. I don't even know if it is tight bark. Here are my pictures to compare
Wolf, The 2nd photo looks like TB to me. I am a little bit on the fence about saying the entire grey area on the tree in all of the photos is TB. But, seeing it on only the top sun-exposed side in the second photo gives me some certainty that TB is present. What is currently the demise of your tree is Verticllium. The combination of the two is eventually deadly. If you do not get new growth to continually emerge to overcome the dieback, the tree succumbs. I myself was hoping for a better response for this tread. It is a bit hard when we step out into the open and try to state a relatively unknown and unrecognized condition is a widespread deadly pathogen infecting maple after maple while we quietly sit by with our heads in the sand. Lack of response, to me, means that people are not interested or they just don't belive that a few of us could get together without any "real science" behind us and validly state a condition like this exists--it plagues a number of species of Acer. A topic of this magnitude warrants some response, and when it is largely ignored, it would seem that it is deemed unimportant. The implcations of admitting this as major problem are great as it will effect everyone in maples. As long as people view maples as disposable, and do not care about their quality, then this will be a non-issue. As long as the demand is so great for the plants that growers can't even keep liners around to grow into 1's and 2's and 5's and 7's--as long as people blindly buy maples without the intention of keeping them for the long term, Tight Bark doesn't exist. I had a contact send me this first year graft (pictured below) from a nursery on the east coast in-trade last winter for scion wood. I think it speaks volumes. If you and others want to post your photos and have a discussion, I am happy to contribute. Additionally, I know that you graft some Wolf as do others on this forum and there are ways we can reduce or eliminate TB in our plants through propagation. At one time, a great deal of work was done in a limited number of places to clean up the TB maples--maybe we should figure out how to start doing it again. This is a prime reason to see the stock plants the grafts you are buying come from and buy a plant that is older. Look for a quality clean maple. Any of us will have a hard time looking at a liner or 1 gallon plant and determining what the future holds for it. But if it costs us $20 bucks at and acution, who cares? MJH
Michael, I have checked my maples and I do not seem to find much evidence of the condition you describe as tight bark. I am very curious to know, if it is a disease, what is the pathogen tha causes it?, are we sure it is not a cultural problem? I thank you for initiating this post which helps us better understanding the culture of maples and, in my case, I will be more careful checking the bark of potential maple purchases. Regards, Gomero
I have a Kagiri nishiki that exhibits "TB". It sat without out growth in a 15 gal for years slowly dying. In anguish, I cut the heck out of it...back to to only the main trunk. It was an ultimatum sprout new growth or die on the burn pile. The plant is now thriving with new sprouts and into it's second year of new life after my attack with the pruners. Perhaps through aggressive pruning TB can be temporarily thwarted.
Interesting, I have a 3 gal Koshiboro Nishiki which has little new growth also. The bark exhibits some of the same characteristices. I have been debating whether to prune back all the branches a good bit. For the last two years it has had a couple of sprouts grow off of the trunk, but then the next year they dont grow anymore. The branches have yet to grow any new growth. Hearing your success, gives me some thought to some intense pruning. I also have a fairly mature 8-9ft 'Karasugawa' that really hasnt shown much new growth. But a graft i did of off it last year, showed exceptional young colorful growth. I might consider pruning his bracnhes to try and revitalize him also. Not so much thinking it has the bark problem, but just the maturity issue some variegates have. Thanks for giving some useful information Mike
Hello , I am very interested in seeing the pictures that you speak of in your post , But for some reason I am not seeing them . Do you know why this may be ? Do you have links so that I can view the pictures ? Thanks for your time L Hi Mike , I just realized you were one and the same Mike that I email on another forum. I also see that you removed the photos so that answers my question about them. Mike my viridis looks as if it has Tight Bark . Today I saw new growth on my long standing very bare maple tree as I have written you about . Like I have said all the new breaks of growth seem to be coming from the main leader only . The few branches that were left on turned a burgandy and grey color . Herer are some links to the photos. The pictures may not appear full size when you open the link so please open them to full size so you can see detail . Let me know what you think . I really appreciate it . Laura http://www.davidbowie.com/users/7TowersSerendipity/bark4.jpg http://www.davidbowie.com/users/7TowersSerendipity/trunk1.jpg http://www.davidbowie.com/users/7TowersSerendipity/trunk2.jpg http://www.davidbowie.com/users/7TowersSerendipity/bark.jpg
What happened here with the trunk on what may be 'Bloodgood'? The photographs were taken in early October of this year when a little critter was visiting. There may have been signs of a cracking at first, but this just occurred this season.
Laurie, The pictures are quite fuzzy and it is very difficult to assess anything, can you try again. Regards, Gomero
Okay. I took another set of photographs today while still different critter was visiting. Thanks for the help!
Laurie, The picture of your Bloodgood look like a triflorum I have. It has a split about two feet long along the entire side and up into a branch. It has only been growing in my yard about 2-3 years, so is a young tree. I am really worried about what it is, too. Can someone suggest whether or not I should get rid of it? Also have the tight bark on an acer p. 'Crimsom Queen' but assumed as was mentioned on an earlier post that it was cultural due to sun scald. The maple was previously shaded by a large oak which died and now gets quite a lot of hot sun. I would hate to lose it if it is going to start going down. I am really wanting to know more about v. wilt. As my maple collection grows, I don't want to let something get started. I have recently discarded about 3/4 of my hostas due to foliar nematodes and would hate to think of losing trees to something that could be prevented with early detection. Am I right in thinking that early detection can keep v. wilt out, or not?
Laurie, Can you give a little more information. You said it just occurred this season? Do you remember how it started, what the bark looked like, etc? Are other parts of the tree involved- have you checked the other branches for signs of decay or discloration? Can you post a photo of the whole tree? I have some photos of lower trunk bark decay that I will post later that differ from your issue. In my case, the soft wood was injured and decayed over a number of seasons, but the hard wood was not involved as it seems to be in your case. MJH
Here are the trunks of the trees I mentioned above that had the soft tissue problems without the hard wood splitting. First two are of a Bloodgood and the third is of a Trombenberg.
I have had a few email reqests to add back some of the photos that I previously withdrew from this thread. Since the removal of the photos does detract from the discussion, here are some supporting photos. I think that some of these were previously pictured and some are new. Not all of them are limited to tight bark as there are a couple of other issues present. TB is limited to the discolored lesions on the bark that look like sun scald at first, being a burnt red-orange and mature to a grey scar.
MJH- on the first picture you post I see an tear/wound/opening in the bark, and underneath a zone covered in a greyish rougher area. Is the grey area the tight bark phenomenon you are mentioning, and not the tear? By 'discolored' do you mean not green, of a different color than the rest of the bark, but grey? Thanks for the photos. I see some evidence on a couple of my maples of these grey areas, so it'd be good to know what it is, and if it's dangerous for the plant, what causes it? Mr Shep, in the fertilizer post, suggests, I believe, that these problems occur when the plant is weakened due to cultural conditions, since these pathogens are already present in a lot of maples when we get them. Any thoughts on what could be the most critical mistakes we can make?
Yes, the areas below and above the "tear" are covered wtih tight bark. Notice the reddish-brown areas in the margin of the lesion, the problems first presents itself with a lesion of this color. The infection eventually moves on or becomes dormant in the infected area and leaves behind what we can consider scar tissue. The "inflexible" area is what we see with the greyish tissue. The effect of this lesion has been described earlier in the thread. What I cannot tell you for certian is why the splitting occurred as it did within the lesion. I would guess it is sun damage as that area of the bark was heated in excess from direct sunlight and the expanion of the tissue underneath caused the split. As you can see it has healed and if of little significance. We see this type of splitting on a much smaller scale, minute tears in the small twigs of some stressed plants when grown in direct sun. I still have yet to fully undertand the inconsequential small splits in the bark of maples, and what significance it plays in determining a cause or evaluating the health of the plant. In the previous set of photos, pay special attention to what has happened to the leaves of the Aka shigitatsu sawa. Keep in mind that the growth that has withered is relatively young. Not a new chute, but probably from last season. There is tightbark on the branch, but that is not what caused the dieback of the leaves. I am adding a few more photos of a Yezo nishiki (taken this week) that I purchased 3-4 years ago. At that time it was pretty healthy and almost as tall as it is now, about 5ft. It was in a 5gal container and it went into the ground at our other home. It stayed in the ground a year and then was dug up and put in a large 7-10gal ceramic planter where it has resided. The TB really began to show up about a year ago, and last year the plant stagnated with little new growth (actually I lost the first set of leaves and I never got a second--the first being lost near the end of June) and the TB ran unchecked, now covering a good portion of the plant. The tree was clearly unable to fight back. It is going in the ground in a week or two and will get a pruning, but I am doubtful it will live much longer. When the trunk becomes gridled with the TB, there is little we can hope for. I post this as an example of what happens when we put too much stress on a tree that has this pathogen in it. I should have put it in the ground and let it be. Keeping in the ceramic planter for two years has been the wrong then to do.
MJH- I have of course very little understanding of this (but hope to learn). Having said that; I have these thoughts: you refer to the browning/reddening of the branch: I read on Mr Choteau's website (still in construction, I think he intends to add the many photos he has taken of maples, leaves, etc,) something about the browning of the branches on maples. His explanation seems to be that this can appear as a result of stress - freezing in winter, pruning mistakes, adverse climatic conditions, excess humidity, excess branching, etc - this browning appears and a fungus - which he says is the Fusarium fungus - can spread. He recommends cutting the infected branches, and using a fungicide. (He doesn't say whether this is a fatal condition.) I have an osakazuki that has one branch with brown/red spots, and thin splits in the bark (although the leaves are fine, which is why I hesitate to cut the branch) - I immediately thought it was the soil mix in the container, and that it didn't drain enough, the particles being too fine (or transplant shock). This because I had read that tears in the bark appearing on trees in general can be due to water/drought stress. May be there are two separate phenomena: really small or minuscule tears on the bark, due to cultural stress, becoming an entrance for bacteria. or a weakening of the tree leading to the tree being overwhelmed by a fungus present anyway - as suggested here and in other threads? I have another question - and thanks again for taking the time to share your experience and these photos: what has been your experience with fungicides? any recommendations?
This condition is not a fungus. It cannot be cured but topical aplications of chemicals. To my knowledge there is no cure except for the "cleaning-up" of the plant through propagation. Pruning can help control the tight bark and good health and good culture can reduce the expression of it in infected plants. It is passed from parent to offspring and can be transmitted in understocks and scion wood that are infected whether or not there are visible symptoms.
