Japanese Maple dieback

[yamadorikid]

Hi bonsai community, just wondering about dieback on japanese maples.
Usually they will dieback to the next node below a cut. But i have one that has excessive dieback and continued passed the node.
The dieback seems to have stopped but just curious as to why sometimes this happens.

The first is a Skeeters Broom with the excessive dieback.
The cut was made before around Winter/Spring and cut paste was used at the time of the cut.


The 2nd is a Coonara Pygmy done at the same time and also with cut paste. This has healed and the dieback back to the next node.

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[shibui]

You appear to have left a lot of wood above the nodes. I try to prune a bit closer to the node so there is less wood to die off. Most species will die back to the node below any chop so there's no point leaving excess
There are a number of diseases that can affect Japanese maples and cause infected areas to die. Usually the trees have mechanisms similar to our immune system but occasionally an infection will overwhelm the tree's natural defences. I suspect that the more dead wood that can be infected the more likely it is that the infection can spread further.

I've also noticed that where there is little sap flow, maples are more likely to die further. I note that the second example has shoots on both sides of the trunk so sap flow will be good so further dieback is less likely.
In the first case there may not have been any viable shoots on the right side in which case there will be little sap flow on that side.

On the positive side, I would cut any chop like these at an angle at some time after the initial prune to give a better looking taper from the thicker section to the thinner new leader.

[Trimmy]

I had dieback on my Skeeter's Broom this year too. ...from the tips of the branches all the way down to the tips of the roots.

[shibui]

I had dieback on my Skeeter's Broom this year too. ...from the tips of the branches all the way down to the tips of the roots.

That sounds like either bad management with watering or, if the tree wilted suddenly in spring, one of the common infections that affect JM if the roots are too wet through cold winters.
I've definitely had much better results with standard JM seedlings than with any of the named cultivars. It might be cool to be able to quote a fancy name for your tree but I'd rather have a really good, living bonsai than a name any day.

[TimS]

I had dieback on my Skeeter's Broom this year too. ...from the tips of the branches all the way down to the tips of the roots.

That sounds like either bad management with watering or, if the tree wilted suddenly in spring, one of the common infections that affect JM if the roots are too wet through cold winters.
I've definitely had much better results with standard JM seedlings than with any of the named cultivars. It might be cool to be able to quote a fancy name for your tree but I'd rather have a really good, living bonsai than a name any day.

After years of chasing the fancy ones I'm coming around to this way of thinking. Only Shishigashira (much more reliable autumn colour for me) Arakawa (lovely bark) and Katsura (spring colour) I'm particularly going to persevere with

Both look concerning, I don't like the wrinkled bark in the green of the Skeeters. Had a similar thing happen with ume cuttings and it was a death sentence

I would persevere with the pygmy until the lower green shoots either grow on or die off too.

[Trimmy]

I had dieback on my Skeeter's Broom this year too. ...from the tips of the branches all the way down to the tips of the roots.

That sounds like either bad management with watering or, if the tree wilted suddenly in spring, one of the common infections that affect JM if the roots are too wet through cold winters.
I've definitely had much better results with standard JM seedlings than with any of the named cultivars. It might be cool to be able to quote a fancy name for your tree but I'd rather have a really good, living bonsai than a name any day.

Yes it leafed out then suddenly wilted. I hadn't watered it much, if at all at that point but it was sitting out in the frequent rain we had during winter. The same happened to my Ariadne and Butterfly. I'm seeing your point about JM seedlings. Less likely to drop dead, plus they grow a lot more vigorously. Much more enjoyable to own. A lot cheaper too.

[shibui]

Sounds like the same problem I mentioned above. Definitive symptoms are bark turns black at ground level.
Hard to control winter rains but the problem seems to occur much more often when the pots are sitting on the ground and/or with maples in mix that does not have enough air circulation. I prefer to repot trees as soon as possible into a mix I know and trust.

[Trimmy]

Sounds like the same problem I mentioned above. Definitive symptoms are bark turns black at ground level.
Hard to control winter rains but the problem seems to occur much more often when the pots are sitting on the ground and/or with maples in mix that does not have enough air circulation. I prefer to repot trees as soon as possible into a mix I know and trust.

Thanks for the tip. Yes, they were on the ground and the potting mix was probably too dense. Lesson learned.

[yamadorikid]

You appear to have left a lot of wood above the nodes. I try to prune a bit closer to the node so there is less wood to die off. Most species will die back to the node below any chop so there's no point leaving excess
There are a number of diseases that can affect Japanese maples and cause infected areas to die. Usually the trees have mechanisms similar to our immune system but occasionally an infection will overwhelm the tree's natural defences. I suspect that the more dead wood that can be infected the more likely it is that the infection can spread further.

I've also noticed that where there is little sap flow, maples are more likely to die further. I note that the second example has shoots on both sides of the trunk so sap flow will be good so further dieback is less likely.
In the first case there may not have been any viable shoots on the right side in which case there will be little sap flow on that side.

On the positive side, I would cut any chop like these at an angle at some time after the initial prune to give a better looking taper from the thicker section to the thinner new leader.

Thanks Shibui,
ill keep an in winter and early spring from now on, most my maples are in my own bonsai mix already, but ill just make extra care during those critical periods of winter/spring, as i had a couple maples die from this disease this current spring.

I have heard some people use anti root rot treatment. Is this something that could potentially help the survival rate?
Does anyone use this on their maples?

[shibui]

It does seem to be fungal so maybe a root fungicide might do something as a preventative.
Personally try to only use treatment when there's a problem. Changing conditions to prevent the problem is my first choice.