Help with declining 37yr old Trident maple

[Neosdad]

I have recently repotted my 37-40 yr old Trident maple and cut approx 30% of the roots and repotted into a training pot with 30% akadama, 30% pumice and the remainder with standard bonsai soil.

I repotted on 18th August. A little late as the new spring growth leaves had already come out at this stage (I live in Sydney).

Since then I've noticed all the leaves started to brown and die off. I cut back most of the dead/dying growth in a attempt to save this tree and it has continued to decline in health losing all of its leaves and zero new growth - even after 2 months.

I put chopped up sphagnum moss in the soil and mist the tree to keep humidity levels up but it hasn't helped.

I nicked the tree on several primary branches and I can see it is still "alive" as it's green but not sure what to do now. Should I put it in a shaded area? It's currently sitting in the same position it has thrived for years prior to this recent repotting incident.

Any advice is appreciated as I don't want to lose this tree.




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[Bougy Fan]

Hi neosdad and welcome. When you say you are misting is is that on top of normal watering ? How often do you water ? What kind of mix was it in before ? General practice is semi shade after repotting. Have you been using a product like seasol ?

Some more info may help with an answer.

[Neosdad]

Hi neosdad and welcome. When you say you are misting is is that on top of normal watering ? How often do you water ? What kind of mix was it in before ? General practice is semi shade after repotting. Have you been using a product like seasol ?

Some more info may help with an answer.

I've been watering less since the leaf loss means less evaporation. Misting of the leaves was done on top of watering and the misting was done twice a day.

Prior to repotting, it was in a premixed bonsai soil from a bonsai nursery. I've been using seasol once a week on the plant and haven't fertilised it since repotting as it is stressed.

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[shibui]

Not sure I would call 18th Aug recent. That's now 3 months ago and the tree should have recovered well before this.
My guess is some sort of infection in the roots. Occasionally that happens to maples and usually seems to be related to the soil being too wet. In that case sphagnum and misting as well as regular watering may all be contributing to the problem instead of helping.
Occasionally trees can recover from such a setback but I'm sorry to say this one looks a little past saving. While there is green there is still hope but that hope is only faint after this long.

[TimS]

Gotta agree with Shibui sadly,

All my tridents were leafing out in August, and now have totally full canopies. Something is very wrong with this one and the window for saving it is rapidly closing if it hasn't already.

I'd start by just scratching a little bit of the bark off with your finger nail , starting at the top and working down, to see if there is any green cambium that would indicate the tree is still alive.

[Neosdad]

Hi @TimS @shibui I thought that might be the case as my other maples repotted at the same time are all flourishing as well. I have made small cuts throughout the tree and I can still see green cambium so it's still alive, just not pushing any new growth. I'll just leave it as is for now and hopefully a miracle will happen and it will push some new growth (although not hopeful).

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