Half dead japaneese maple

[MattWolf777]

Hello everyone, thank you for reading!

I bought a japaneese maple in 2025 spring for a really good price. The nebari is a beast, about 40 cm in diameter... The reason it was soo cheap is half the tree is dead...

I Do not think a wound this severe is healable...

If I were to carve the trunk out, and treated the inside with epoxy, could I keep it as a hollow trunk long term?

Is it possible to maybe graft cambium layer as a cover on the wound?

What else to do?

Thank you for answers!

 

[dbonsaiw]

I Do not think a wound this severe is healable...

Healable and what it looks like as a bonsai may be different questions. My assumption is that you will end up with something like my tree in the pic attached. I guess you could use approach grafts across the dead part to help close up the wound. Again, may not look great as a bonsai.

 

[Bonsai Nut]

"It just so happens that your tree here is only MOSTLY dead. There's a big difference between mostly dead and all dead. Mostly dead is slightly alive." (Apologies "The Princess Bride")

What you have here is a grafted Japanese maple whose graft has failed. The cultivar above the rootstock has died, and you are left with the rootstock. The good news is the rootstock is typically chosen because it is strong and resistant to disease, pests, etc. The bad news (if any) is only if you cared about whatever cultivar was above the rootstock.

I would not worry too much about the deadwood right now, and focus instead on not only getting the new leader as healthy as possible - but to wire some movement into it if it is still bendable. Once the tree gets strong, it will start to compartmentalize its growth away from the deadwood stump, and it will be much easier to decide what to do with it - whether you want to keep it as an artistic element, hollow it out, or try to get the tree to grow over it.

Be careful about keeping too many branches at one junction because it can cause an insightly lump of growth. I would personally consider eliminating them all except for the main leader - making sure you seal all the wounds.

 

[MattWolf777]

"It just so happens that your tree here is only MOSTLY dead. There's a big difference between mostly dead and all dead. Mostly dead is slightly alive." (Apologies "The Princess Bride")

What you have here is a grafted Japanese maple whose graft has failed. The cultivar above the rootstock has died, and you are left with the rootstock. The good news is the rootstock is typically chosen because it is strong and resistant to disease, pests, etc. The bad news (if any) is only if you cared about whatever cultivar was above the rootstock.

I would not worry too much about the deadwood right now, and focus instead on not only getting the new leader as healthy as possible - but to wire some movement into it if it is still bendable. Once the tree gets strong, it will start to compartmentalize its growth away from the deadwood stump, and it will be much easier to decide what to do with it - whether you want to keep it as an artistic element, hollow it out, or try to get the tree to grow over it.

Be careful about keeping too many branches at one junction because it can cause an insightly lump of growth. I would personally consider eliminating them all except for the main leader - making sure you seal all the wounds.

Thank you very much!

I knew the trees were grafts at one point. They should have been planted in a hotels garden years ago, but the hotel canceled the idea last second, even tough the trees have been shipped and paid for... Talk about fraud... Afterwards the landscaper put them in his garden, but abandoned them pretty much, that is probably why most died, and the rest barely survived. What a pity...

As for the branches, I will not leave that clump, but I repotted in late april when I got it, I left it untouched to recover. The rootball was all clay, I had to take it apart with a pickaxe, it was literally like a geode...

Thank you!

 

[MattWolf777]

Healable and what it looks like as a bonsai may be different questions. My assumption is that you will end up with something like my tree in the pic attached. I guess you could use approach grafts across the dead part to help close up the wound. Again, may not look great as a bonsaI also thougt

Healable and what it looks like as a bonsai may be different questions. My assumption is that you will end up with something like my tree in the pic attached. I guess you could use approach grafts across the dead part to help close up the wound. Again, may not look great as a bonsai.

Thank you!

I also thought about approach grafting, but will probably create a hollow, and experiment with epoxy...

The nebari is better on the healthy side anyway, so the dead part will be in the back. I do not really mind how the back looks like, but I'm more concerned about the longevity of it, and how to mitigate rot.

 

[leatherback]

I would for now pot it up properly, it sits way to high. Make sure you cover the roots completely. Then select one branch as a leader and allow that to grow. Once you see in the bark a ridge between living and dead you can smoothen out the dead area, and treat it with wood hardener. Such a wound can certainly be fully closed, if you allow the top to grow for a few years, use cutpaste and at least once a year scar the wound edges.

 

[MattWolf777]

I would for now pot it up properly, it sits way to high. Make sure you cover the roots completely. Then select one branch as a leader and allow that to grow. Once you see in the bark a ridge between living and dead you can smoothen out the dead area, and treat it with wood hardener. Such a wound can certainly be fully closed, if you allow the top to grow for a few years, use cutpaste and at least once a year scar the wound edges.

Thank you Jelle!

I was thinking, more than half of the tree being dead is beyond wound healing, but you telling otherwise is reassuring.

Yes, I will plant it deeper in spring. I have a tendency, to plant too high...
Do you think making small scars around the base, and applying rooting hormone in spring is a good idea? Ground layering is what I think it is called.

Thank you !

 

[leatherback]

in spring

why not just fill it up now?

Do you think making small scars around the base, and applying rooting hormone in spring is a good idea? Ground layering is what I think it is called.

no. You need to get this nice and healthy. No tinkering.

 

[MattWolf777]

why not just fill it up now?

Good point!

no. You need to get this nice and healthy. No tinkering.

Got it! Thank you!

 

[Shibui]

Do you think making small scars around the base, and applying rooting hormone in spring is a good idea? Ground layering is what I think it is called.

You already appear to have good roots all around the live section of the tree. The section that does not have roots is right under the dead part. Roots cannot grow from dead part of the trunk. There's no point layering unless you are planning to develop new roots around the live part to replace the current roots.

If I were to carve the trunk out, and treated the inside with epoxy, could I keep it as a hollow trunk long term?

Epoxy is not a wood preserver. Mostly we use epoxy to fill hollows so the bark can grow over and heal a wound.
Usually only the dead wood rots away. Many trees can live for hundreds of years with hollow trunks. Rot does not usually continue to infect and kill the living part of the tree.
Wood preservative like lime sulphur or one of the newer wood hardeners can slow the dead wood from rotting after you have carved out an attractive hollow but all that is getting well ahead of yourself. As @leatherback pointed out, you should have a couple of years before you need to tackle further work on the tree. Spend a year or 2 getting it healthy and strong.