Maple bark cracking open - what’s happening here?

Messages
1,054
Reaction score
1,930
Location
Tennessee
USDA Zone
7a
Hi everyone! It’s been a minute and hope everyone is doing well.

i have a small Japanese maple that has been growing healthy for the last couple years, but recently I found a concerning split in the bark of the trunk. When I gently press on this area the bark sinks in as if there is a depression beneath.
EE260A67-7CD6-485D-B1E7-8BCEEF965A49.jpeg

A830B79E-BD79-426F-B8C6-5685FA6F1B54.jpeg
This is the first time I’ve seen something like this and I’m wondering if anyone else has experience with this happening in their Japanese maples and could offer some advice?
 

Shibui

Imperial Masterpiece
Messages
5,622
Reaction score
10,836
Location
Yackandandah, Australia
USDA Zone
9?
Hard to tell just from photos.

Sometimes bark cracks open from growing stress. Those usually just heal over naturally.

Damage to the bark can look similar. Damage can be from physical injury like something dropped on it or it fell off the table and hit something. Damage can also be from sunburn, especially after defoliation or pruning in hot weather.
Probably not a lot you can do now except monitor it to see how far the problem actually extends. Healthy bark around the edges will continue to grow and thicken while the damaged area will be thinner and often wrinkled. You could try exploring by flaking off outer bark but that can be unsightly and may even damage healthy bark so I'd just wait to see.
When you can see the difference you can remove dead sections. The underlying wood should still be solid for a few years and natural growth will usually see a callus start rolling over the edges. Wound sealer can help progress and if it's not too big there's every chance the tree can heal right over the damage.
 

Bonsai Nut

Nuttier than your average Nut
Messages
11,311
Reaction score
23,511
Location
Charlotte area, North Carolina
USDA Zone
8a
it’s just trees all the way down.
Love the reference :)

I hope I am wrong, but that maple looks pretty sick to me. Yes, bark can crack when a tree is growing, but your tree appears to be wilting, and I don't like the look of that bark. I am concerned that the tree is too wet, or the roots on that side have been compromised, or the trunk was injured in some fashion, and you have rot/fungus in the trunk that is working its way up towards the apex. That whole side of the tree may be dead.

I would investigate further, and see if that cracking bark is actually dead/dying. See if it pulls away from the trunk easily. What you want to see is if there is fungus in that section of bark, or fungus in the trunk under the bark. If so, you will need to remove as much of the diseased bark as possible, cutting back to healthy bark with a sharp knife/razor blade, dry the area, and treat with both topical and systemic fungicides. Lime sulfur is a great topical fungicide if you have any around. Keep the wound as dry as possible - do not water the upper part of the tree or allow it to sit in the rain. Only water the soil and only when the soil is very dry.

I would also recommend reading up on maple cankers. And be aware - maple fungus can spread easily so you may want to quarantine this tree away from your other trees. Make sure if you use any tools on this tree (to prune, etc) that you sterilize them before you use them on something else.
 
Last edited:
Messages
1,054
Reaction score
1,930
Location
Tennessee
USDA Zone
7a
Damage can also be from sunburn, especially after defoliation or pruning in hot weather.
This makes sense. My yard is Dante’s inferno at the best of times and my normal spot for maples saw way too hot temperatures in a very unseasonably warm June. I’ve rigged up 30% shade cloth over these locations the last couple weeks but I notice the whole side of the tree pictured looks a bit different than the side that was facing the wall.
 

Scorpius

Shohin
Messages
275
Reaction score
356
Location
Northwest Indiana
USDA Zone
5b
Not to be the bearer of bad news, but this JM is in rough shape. The foliage and branch dieback all look weak and unhealthy. The substrate looks wet and I can only guess there is some major root rot going on.
 
Messages
1,054
Reaction score
1,930
Location
Tennessee
USDA Zone
7a
Thanks for the advice folks. Looks like this tree is bound for the burn pile before it’s said and done. I cleaned up the area and there is a lot more damage than I would have ever thought. Popped it out of the pot as well and while nothing smelled of decay or rot, not much healthy root action going on.

29C756AF-728F-48C6-B0FD-A8CE19A84F1F.jpeg

This tree went through the Nashville tornadoes couple years back and lost its apex and my suspicion is that there was trunk damage that wasn’t seen and this area has just been rotting out for months and months.
6D9ABD12-52BF-4DA8-8AE9-6C9C67F02AFB.jpeg

I’ve cleaned up all of the dead bark and cut back to living tissue. Checked the rest of the trunk and roots and no loose bark anywhere else. I’ll keep this guy protected from the upcoming monsoons and hope for the best.
B73C54FD-ED42-446B-9C39-CE96CB8009CB.jpeg

I am seeing it trying to bud along most of its branches, so maybe there is hope? Regardless, this discovery has been a real bummer.
D480EF6D-6D9C-444B-9B26-FF869ED63C92.jpeg
 

BobbyLane

Masterpiece
Messages
4,644
Reaction score
13,897
Location
London, England
Looking at the rootball, the mix doesnt look like its staying too wet, but the top does. Id clean off the rest of the moss and any other crap like spent ferts, muck etc.
Looks like the tree is entering a new chapter as a hollow trunk bonsai.
send it to me if its deemed surplus😎
 

Bonsai Nut

Nuttier than your average Nut
Messages
11,311
Reaction score
23,511
Location
Charlotte area, North Carolina
USDA Zone
8a
Regardless, this discovery has been a real bummer.
Always sucks when you lose a tree, but I wouldn't give up hope yet. It is really important to treat it with fungicide! Lime sulfur the deadwood, and buy some systemic, and the tree may pop back.

I lost a big landscape red maple this year to some sort of canker causing fungus. 24" diameter trunk. In two years went from perfect to dead... despite me spending a lot of dollars trying to save it. Fortunately bonsai are much easier to treat! And you don't have to pay someone to come remove a dead one!
 
Last edited:

Katie0317

Chumono
Messages
771
Reaction score
821
Location
Central Florida
USDA Zone
9B
I just finished reading a Peter Tea article about a maple he had and a hole in its trunk that hadn't healed properly during the years he'd been in Japan. He dug out the area of the hole and the area around it and put in a quick drying cement. I read a lot of his maple articles in one sitting but this one was one he wrote after he got home...So rather late by date. You can find his blog and there is an index on the side that allows you to see his posts and read the one you're looking for.

This one was written after he'd gotten home and began working on the four remaining trees he still owned. They'd been unattended during the two years he was away in Japan. It was a trident but it may be of interest to you. Am not sure it will be completely relevant because his was already dried out if I remember correctly. Give it a read though and see if there's something in there you can use.

Good luck, would hate to see you lose this.
 
Top Bottom