I have about 10' Glowing Embers Japanese maple that I planted last year, and I just noticed that the trunk seems to be damaged on one side. I can't tell if this is recent or it happened last year. The tree is in shade in morning, and in full sun in afternoon, and this is the side directly towards sun. Also, in the bottom of the picture, you can see that even where bark is not gone, it is still discolored, which got me thinking that this might be due to sun exposure rather than some animal. Is this possible, or does someone have a better explanation? I'm in central Texas.
The sun exposure explanation is very likely in this case. Especially in Texas where the sunlight is strong due to being quite far south. Sometimes it can happen in the winter when the sun angle is low and more directed towards the trunk and there are no leaves to provide any shade. Often with new trees the bark growth is not fully hardened, due to being grown too fast at the nursery, or the plants are not used to strong sun on the bark, due to being grown close together and shading each other. Also, if you plant a maple with what was previously the north facing side towards the south it could have a negative impact regarding sun damage. Hard to tell the long term impact on your tree from the one picture, if it is a strong tree it might recover and encapsulate the damage with wound wood...
I agree, it looks as though it's been badly burned. The brownish color is characteristic, lighter than you would see with an infection. I think you're in with a good chance, and eventually (3-5 years) the damage won't be visible any more. Here are a few things you can do to help. - Get some soluble copper treatment, and pulverize over the entire trunk. Do this every 3 weeks all season. - Clear the grass in a circle about 2-3 ft radius around the trunk. - Put 3-4 inches of wood or bark chips on the cleared area, but don't mound it around the trunk, try and keep the trunk clear by leaving an inch of bare earth. - Get some burlap wrapping. If it's very dry there, you can wrap the trunk directly, if wet, use 3 tall stakes so that the wrap stays clear of the trunk. unwrap/rewrap for copper treatments. - When you water, water the mulch copiously, don't water trunk or foliage. In a couple of months, if there's no sign of blackening, you can stop the copper, and let the tree spend some time unwrapped; but it there's a heat wave or really vicious sun, wrap it up. Keep mulched for the next 3 years, minimum. What happens is that the bark in the sun gets hot, and dries out, hardens, and can no longer transport moisture. Good luck, -E
Thanks for info and suggestions. For soluble copper, did you mean liquid copper fungicide, or something else? Is this sun damage something that affects young maples more and it will eventually grow out of it/get used to sun, or will I have to keep it wrapped with burlap every summer? Thanks, Tom
Tom, yes it's usually some form of copper sulfate. Copper is also a great bactericide, so it will give you protection against both saprophytic fungus like coral spot, and also bacterial infection of the damaged tissues around the wounded area. As you probably guessed, the reason to clear the grass competition and mulch is to provide more defensive moisture to the tree. Over time, the main trunk will toughen up, the root system will be more robust, and the wraps should be unnecessary. (Especially if this happened because it was in a greenhouse or shaded, as Maf suggested.) But in times of drought stress and really bad sun, burning is always a risk with JMs, which are mostly quite thin-barked trees. -E P.S. the "good" news is, the "wound wood" that the tree makes to compartmentalize the wound is usually thicker than the original bark.
Quite right. Where I worked, there was a row of "Sapporo" elms, the ones that replaced the local ones that were diseased. All of them had some bark damage at the base of the trunk. I tought maybe one of my fellow-teachers had had a difficult evening with friends, but the damage were all oriented South/South-West, which corresponds to when the sun here is at its peak. I also had some damaged bark on a couple of my maples, and I did what Emery suggested : (remove the dead bark), use copper (Bouillie bordelaise, Bordeaux mix) and after a few years, everything was OK. From what I can see, your tree is not sick, the new" hem" on the damaged part shows it's recovering. I have a big Acer palmatum palmatum that encountered the same problem : I let a Lonicera nitida grow up to about 2-3 feet, and now the lower branches also some shade in the hottest days of summer. It's fully recovered now. Too dark now to takes pictures, maybe tomorrow...
