I planted a JM Osakazuki in my mom's front yard last year and it seemed to be doing fine. However, this season only one side of the tree is producing leaves, it splits into two branches at the bottom. The leafy side's bark looks a little greener but the other side dosnt look like it is dead. What is wrong with it? Is the other side just slower growing? I live in the central valley in California, USA
Hi, it's impossible to be sure without a photo, but unfortunately dieback of large branches over winter is relatively common in newly planted Acer Palmatums, especially if they have been subjected to stress, or recently arrived from the nursery. I guess you just need to give it a bit more time to see if the branch is alive or dead. If the branch does turn out to be dead, the best option is to cut it off as close to the main stem as possible. The other half of the tree may be completely ok, I've had an Osakazuki lose its main stem but regrow with no problem from the lower branches.
Bacterial blights etc. a common complaint with grafted Japanese maple cultivars. By now hundreds if not thousands of people will have asked on the internet about dieback of Japanese maple cultivars. Start by looking for information on - Pseudomonas - Verticillium on maples.
I uploaded some pictures of my tree. I think the branch is dieing. Thanks for the help, Im probably going to just lop it off real close like you said and train the other side more upright.
The canker-like blackening on the dead stems is commonly seen, you should be able to find discussion of this specific condition (Pseudomonas?) by searching this web site and others. The entire top may go on to fail, as this problem can be aggressive - indeed you have already lost half of the top of this specimen.
Indeed, the black area near the "V" where the branches join is the root of the problem and seems to extend beyond the seemingly dead stem. I cannot comment on which specific pathogen is causing the problem but it doesn't look good. You can remove the dead branch and see what happens, this is the sensible first step, but I think eventually you may lose the whole tree. Sorry to be negative but the pictures do not give much grounds for optimism.
At one time, I was losing my most beautiful tree, a Seiryu, branch by branch, to this disease or one of its cousins. Figuring I had nothing to lose, I tried a radical approach. First, any branch that was entirely girdled, all the way around, with the black "bark of death" I cut off. A branch that is girdled only partly around can perhaps be saved. I cut off ALL of the diseased bark with a single-edge razor blade, cutting back to healthy green cambium. At the time, it seemed very extreme and desperate--on some branches I cut off the bark two thirds of the way around the branch. My goal was to leave no obviously diseased tissue on the tree. I don't know if cutting out the diseased tissue did the trick directly, or if what helped was the tree's own defensive response to debarking. But the tree has recovered fully, despite some rather massive scars (which are slowly closing). Might be worth a shot, anyway. Good luck! D.
