Bonsai Maple tree main and most of the trunks turned black (anyone could help please)

[ryu.yugi]

Hi guys,
Hope you all well.
I have given 30 years old maple bonsai tree, 3 weeks ago. And already have blackened trunks but not as bad as this.
3 weeks ago still have new small trunks and small leaves to start growing.

Last week i have repotting the tree, cutting a lot of roots, with hope i could still save this bonsai tree.

I am very new with having bonsai tree, so would need some helps from you guys.
Hopefully i could do something to save this bonsai.

I don’t know what happened and if this a diseases which could not be treat anymore as looks like it’s spreading. At the moment still have maybe 25% or less green trunks.

Please see some pictures, so you guys could see the situations here, by the way it’s in Sydney weather now is spring to summer.


Thanks so much to read and help in here

 

[0soyoung]

"Black" bark on acer palmatum usually means the cambium underneath has died, but sometimes the bark darkens over the winter and nothing is wrong, it greens back up after it has leafed out.

If the cambium died recently, the black areas with be soft and punky, maybe even wrinkly somewhat like a raisin. In this state the bark will easily slide off. After a while it will desiccate and the dried black bark will be tightly adhered but depressed from the level of the clearly green bark. You can verify this state by scraping the area with your thumb nail. If you see green, it is alive and maybe will be okay. If not, the cambium is dead in that area. Given a little more time it will bleach to tan and maybe white and eventually will flake off.

During winter there are only two things of which I am aware that might do this. One is pseudomonas syringae. The other is simple desiccation; the tree maybe was exposed to wind and bright sun while dormant or simply wasn't watered sufficiently. There may be patterns to the dark areas that allow you to deduce which, if any of these was the cause of "black bark" areas.

If you cannot figure it out from here, respond with some more detals and someone here will have a better chance of helping you with this.

 

[j evans]

I froze a couple and they turned black.
Welcome!

 

[AlainK]

Where are you from? The green trees in the background makes me think you're in a temperate part of the northern hemisphere.

I'm afraid your tree is a goner. To me it looks like pseudomona. When treated from the start, the tree can be saved, but now I fear it's too late. Sorry.

 

[BunjaeKorea]

Welcome.
First things first. That tree is very unlikely to be 30 years old from the characteristics it has.

Second, the tree could have been frozen but that is very unlikely this time of year.
There are some fungal diseases that do this especially in maples. In which case burning is the best option to prevent spreading to other trees. The trunk has turned black so it is very unlikely that it will survive.... more likely it is already dead.
As you have bare rooted it (removed the soil) while it was weak, if it wasn't dead before it likely is now.

Don't take it too hard. Just hit the books and try again

 

[AlainK]

As you have bare rooted it (removed the soil) while it was weak, if it wasn't dead before it likely is now.

I hesitated to add that to my comment, but I totally agree.

 

[BunjaeKorea]

I hesitated to add that to my comment, but I totally agree.

Sadly, it's a fact ..... many a tree has been killed with "kindness". Got to learn somewhere.

 

[ryu.yugi]

Thanks so much guys for all the replies, really appreciated it..
The root was still really fresh.
This is the current condition : almost all the black has turned light browns now, still hope it would recover.

 

[Gustavo Martins]

almost all the black has turned light browns now, still hope it would recover.

Not sure that's a good thing... Scrape some of the bark off and see if it's green underneath. If not, it's just dead and dry... Hope not!

 

[Yosemite Goat]

On one of my maples I had two black stems last spring. Since those stems did not affect design I just cut them off well below the discoloration. Then I burned the stems. I have not had signs on any other stems.

I was not able to determine if the cause was infection or freezing temperatures.

 

[August44]

I think the black on the branches/trunk is Pseudomonas syringae, a fungas that I find on my collected conifers every so often. The pictures are of a recently collected Subalpine fir that I have already treated with Copper Sulfate. I think one has to be very diligent about spraying in order to get rid of it. I collected another SA 3 years ago with the problem but did not know what it was or what it would do to the tree. The tree was slowly dying (loosing needles and branches dying) I started spraying it early this spring and now see some buds coming. The trees I collect up high are covered with snow for 7-9 months of the year and I think that creates an ideal condition for this fungus. Now that I understand what it is, I probably won't collect any more trees with the black on them.

 

[0soyoung]

Pseudomonas syringae, a fungas that I find on my collected conifers every so often. The pictures are of a recently collected Subalpine fir that I have already treated with Copper Sulfate.

Pseudomonas does indeed affect also maples in a similar fashion, but it is a bacterium, not a fungus.

Indeed, cooper sulfate or 'copper fungicides' as well as Bordeaux mix (copper sulfate + lime sulfur) are effective treatments. So too is hydrogen peroxide that used to be the antiseptic included in first-aid kits.