I have two large, multi-trunked Acer palmatum Moonfire that are showing ugly bark damage on trunks and branches facing southeast, where the sunlight comes from. I have suspected verticillium, but trunks and branches that I pruned off show no wood discoloration, (that at least according to my research is the telltale symptom of that disease.) They also continue to leaf out each spring despite the apparent damaged bark, and have had neither leaf drop or wilt. I'm attaching recent photos. I'm perplexed and could really use some advice from an expert.
I have no idea other than sun scald, but I am a novice and far from expert. I hope you find some good advice here!
Thanks so much for your response, Maplesmagpie! I'm still not sure what it is. I think because there is no discoloration of the wood of several trunks and branches I pruned today, I can probably discount verticillium. I've also done some research on sun scald (at your suggestion), but the damaged areas previously pictured seem sound (no loss of bark, breaks, or sunken areas of dead bark.) Despite ugliness of the blemishes on the surface of the bark, it at least appears to be functioning normally. I'm holding off on any draconian measures for the time being, (and even took some scions for hardwood rooting.)
Between Tight Bark, verticillium, and all the other problems with Japanese maples discussed in this forum, one thing I'm wondering is....how common is all this? After reading these posts I feel like, as a new Japanese maple enthusiast, I've taken on a risky hobby with touchy plants that need constant monitoring and (ack) yearly spraying. I've long been a tree enthusiast, and have grown gardens of trees for many years....I'm used to planting them and having them thrive. Are JMs so different? Can someone with more experience chime in? I have a small city yard with about 30 JMs. Am I going to be losing many of them randomly, slowly, over the next few decades? Like directorrod, when I see unusual bark on my maples I worry about what it could be. Could someone, or someones, chime in with more details on what bark like that means, and about how common JM diseases really are?
for the maples the correct watering is very important,i suggest use pine bark around the trunk o another vegetal cover like pine cone or leaves of pine .maples want soil with high umidity but with well drainage. the soil should not become dry ! of course usda zone is important ,and the mulching in some zone is not important ,i use mulching in summer for example because i have clay soil and in winter is very wet!
in this forum there are a complete FAQ about bark damage and about verticillum pseudomas etc. ;) for my personal experience the only way is several prune and copper solution low solution similar one paste and give wit the brush
After my initial post I got a good deal of education in a very brief time. Unfortunately, what I learned wasn't good news. I think the two Moonfire I planted 5 years ago were most probably infected with Tight Bark when I got them. The symptoms seem to most closely resemble that condition, (rather than others that I've researched and discounted.) These trees were beautiful and seemed very healthy for the first few years. If there were any symptoms during that time I failed to notice them. I'm usually pretty good about sterilizing my pruning tools, but I must admit that in my enthusiasm I occasionally forget. I think that I'm paying the price for that carelessness. I'm posting two macro photos of the damage on the 2 Moonfire (same trees as in my initial photos,) and then one macro of an Ogurayama that I probably pruned with the same tool without properly disinfecting it. You can see that I've spread the condition to that cultivar too.
Picture 3 is interesting, because it shows that the cambium underneath the scarring is alive and capable of healing. This is a good sign, it may mean the bark is disfigured but not dead; you can check under the heavily scarred areas by doing a scratch test (although you may need to use a box cutter to do it): if the underneath is green, the bark is still alive. My experience is that maples from section palmata will sometimes show damage like this in response to pseudomonas or scalding (either from sun, cold wind) or both. This happens most frequently when a young plant isn't "hardened" into it's garden location. The damage remains superficial enough that the cambium isn't killed (or at least isn't completely killed), the whitish scar tissue is the tree's response. In such cases the tree may recover, although parts of the bark may remain disfigured for years it will show less as the tree ages and the bark turns brown. I don't know from "tight bark". I mean, no one has explained to me exactly what pathology it represents. Maybe I just haven't gotten it, but when I search the web for "tight bark" I don't find a lot in the literature. YMMV. Alex is right on, copper is the best weapon for damage like this. HTH, -E
Would agree with Emery on this one, myself i also don't quite understand the 'tight bark' syndrome that quite a few people have commented on over the years. Yes i have a number of JM which show the tell tale signs of this debate but to be fair they all keep budding and leafing out every year with out fail. I appreciate peoples concerns that 1.The tree doesn't look very appealing to the eye especially when dormant and 2.People are trying to correct something in which in my opinion is nothing more than the bark of the tree scorching from being situated in the wrong position and receiving to much sunlight plus not been hardened out enough. Most of my JM were bought in when young grafts then planted out the following year and up to press these are growing nicely as i would hope for and are showing no signs of tight bark/scorching. The only times when i do see this is when i buy in larger trees which have been brought on by commercial nurseries and have been kept in poly tunnels now wether this has a bearing on the development of the tree i have no idea? All i can say is that once i have planted out the larger bought in trees,they will after a few years start to show signs of improvement in the condition and overall appearence of the tree. Pictures of one of my Pendulum Julians bought this in 2011 was in a very small pot and the overall condition was very poor the entire colour of the bark was yellow and in turn was covered in the scorching/discolouration, didn't really want to buy this but this was the only one left (suprise) it's redeeming factor was the crazy bendy main trunk structure this really captivated me to buying it and seeing if i could turn it around. The last two pictures are from today and as you can see the colouring is now starting to turn back into a delightful olive green and the scorching is gradually fading slightly year after year,although i don't think it will disperse completley it certainly looks more healthier than when i bought it, plus it also matches the other four PJ which i have spread around the garden with regards to the bark colour. I could be totally wrong in my opinions but i do see changes in my trees which are affected by this phenomenon and until some one comes out with a out and out definative cause of this appearence on the bark, i will just continue and treat mine in the way mentioned above and try not to worry to much about this.
Many thanks to emery and ROEBUK for their recent posts. All the advice you offer makes excellent sense and is very much appreciated. On Monday I will send off specimens of these trees to my Cooperative Extension laboratory in Carbondale, IL for analysis. I've had some very good communication with them via telephone, and believe that they will be able to give me a definitive prognosis. Since the people on this thread have been kind enough to share my interest in finding out the cause of these symptoms, I will post the results here as soon as I receive them.
It's the famous Bordeaux Mix (Bouillie Bordeaulaise). Or whatever the consumer equivalent is. The product I buy (made by KB currently, but I don't always get the same brand) is a blue granular powder which lists the active ingredient as 20% copper. I keep a cheap 1 liter spray bottle with the mix for spot treatment of pseudomonas. (Since the climate here is _really_ wet and hovers near 0C many nights during the winter, pseudomonas are a major problem.) The stuff is grainy, so every now and again the bottle gets clogged, I get a new one if I can't clean the nozzle. Basically whenever I see a problem, I spray it. I spray all potted maples before bringing them into the dry for winter, and usually spray again at least once during the winter. For in ground maples I use a lance sprayer/atomizer, usually after leaf drop an again in early spring (late Feb here) before the early ones start to leaf out. I try to avoid spraying leaves, but it doesn't seem to do much damage.
about copper ditto emery ,i use the spray for preventive mode . for bark damage i use brush and low solution of water
pics are best than 1000 words :) put copper like dust with water in one container .in one pics graft point damage (hot temperature 43° summer 2012) on Acer pectinatum Mozart,in another graft point damage (summer 2011 44°) on Acer rubrum Candy ice now with copper the damage is well rimarginate .i use copper on big branch pruned
Alex, when you make your 'paint-on' mixture, do you add just enough water to dissolve the copper dust/granules? Or do you mix it up in the concentration indicated on the label for spraying, but paint it on instead of spraying (so that you get a more focused/concentrated application to the affected area)? I have been using Phyton 27 http://phytoncorp.com/products-overview/# as a preventative treatment in spring (usually apply twice before leaf-out), and then as an active treatment on any trees that have issues crop up during the rest of the year. The Phyton concentrate is a thick liquid, more black in color vs. blue, but I'm assuming that it is essentially the same product/active ingredient, and therefore could be used in the same way (ie, painted on targeted area)?
for the use paint-on the percentage is 40% copper ,60% water .i use copper because is BIO certificated and for me is important :) i not know Phyton 27 but i presume is possible the paint.on use try in one maple only for the first time
You are right and you can paint large ; the product is cooper sulfate pentahydrate . The différence with Bordeaux mixture is that a part of the cooper change in oxychlorure. For use it is best. Remark: As fruit trees grower for 50 years , i observed that symptoms of bacterial pseudomona syringae on Apricot trees and Acer palmatum are the same . My grand father was used to pulverize Bordeaux mixture on Apricot trees in december, but now we think cooper oxychlorure is a beter prevention. I use it on Acers from december to februari . But in march we use cooper hydroxyde (as for Tomatos in summer). With oxychlorure in winter and hydroxyde for leaves , we pour out less cooper (1/10 ) for more effects; and certicated bio . That is what they do in italian orchards too.
We have some Acer palmatum varieties with damage identical to your photos. Ours was brought on by the coldest winter on reccord a few seasons ago. Widespread areas of pseudomonas set in March and April that would double in size overnight. Once treated the areas turned grey and flacked away showing more of the color in your photos underneath. Much of the light brown color was exposed after the next winter and was even more apparent in the 3rd season after much of the light grey flaked away. The healthy tissue from the other side of the tree will form wound wood or healing underneath the dead light brown tan tissue. Eventually it will close and the light brown dead tissue will decay away. Right now it is protecting the heart wood from decay. Just let the tree continue to heal itself and watch the tree for further outbreaks.
Another example. February 2013, the tree had already begun to heal after applying copper: October 2014: May 2016: The full tree in May 2015:
