OMG I need a plan! – Trident Maple

[AGentleman]

Hello everyone,

This is my first post. Firstly, I’d like to thank everyone on this forum for generously sharing their knowledge and wit. It has been both informative and entertaining to read your posts.

I completed a three-day bonsai course in early spring 2024. So, of course, by mid spring, I had planted a trident maple in my wife’s ornamental native front garden. The tree came from a local bonsai nursery, and I planted it without disturbing the roots.




I plan to root prune and chop the branches, as marked below, in early spring when the buds start to swell. I’ve read that newbies often don't prune roots aggressively enough, so I'll try to remove a substantial amount of roots. Afterward, I'll replant it in my wife’s ornamental garden to allow it to grow new branches.



My goal is to have a tree around 50cm tall, informally styled as an Informal Upright. I’m not concerned about having a thick trunk.



Since I need to chop the branches off anyway, I’ll try to air layer them now (early autumn). I’m not sure if it's the best time to do this, but it doesn't matter much if they fail. I can’t leave the tall branches in the garden much longer, and I’m already pushing my luck by attempting to keep the pruned trunk in the garden next spring.

As you can see, the title of this thread is a bit of clickbait. I do have a plan, but it might be nonsense! Please let me know what you think.

Thanks, Greg

 

[Carol 83]

Welcome to the forum! I'm sure some of the Trident experts will chime in soon.

 

[Deep Sea Diver]

Welcome Aboard BonsaiNut!

btw: @Shibui is pretty darn good with Tridents. He’s from your neck of the woods so to speak

We have a number of tridents in ground and others intensively getting their roots worked.

A few thoughts. The basic plan is decent.

One might focus on being intentional with every process done to the trees. Timing is very important as well as technique.

Air layering - there is no advantage in doing an air layer if the tree is not actively growing. Likely if no disease creeps in, then it will just sit there static until the tree goes active and the leaves start producing in spring.

Cheers
DSD sends

 

[AGentleman]

Thank you for your reply @Deep Sea Diver .
I've read many of Shibui's posts and seen his root pruning!
That's great advice about being intentional. It's definitely something I'll try do. I'm too excited of course (it's a good feeling).
I'm not sure the tree has stopped growing, it's 30C (80F) at the moment and quite sunny. The elm next to it is still shooting.
I thought I'd just try to do some air layers to learn the process, however I don't want the tree to get diseased. I might have to practice patience instead
Greg

 

[Shibui]

My tridents also seem to grow slowly all year round, especially in the ground. Was looking at the field grown trees last week thinking they are still quite small but also remember thinking similar in past years but still found the trees well grown by the time winter came so I suspect there's still plenty of growth this year.

Your planned trunk chop looks good but I now don't plan any trunk work until I see the roots. Your planned chop needs the trunk to stay approximately the same planting angle so what will happen when you dig and find the roots are all higher on one side or the other? My approach is: dig first, root prune then work out what to do up top to match the nebari. If you are very lucky the roots will allow you to follow the plan or you may find you can adjust the roots to fit the planned top prune.
Definitely keep the plan in mind but be prepared to change if necessary.

 

[AGentleman]

Thank you for your advice @Shibui . It seems simple and obvious now that you mention it but I hadn't even thought about the nebari matching my plan! I'll definitely dig first.
I'm hesitant to go against the advice of Deep Sea Diver but after your comment about local growing conditions, I might try a couple of air layers on the upper branches. Really just to actually see in real life what I've seen on the screen. Heeding DSD's advice, I'll remove the layers before winter if roots don't grow to avoid disease. I guess the air layering will retard the growth of the trunk but I'm okay with that.
Thanks again,
Greg

 

[Deep Sea Diver]

If you are going to do a layer, keep it on.

Since Melbourne has such a long growing season, likely you’ll be ok if an air layer of chopped sphagnum and media is used and the trunk is sprayed with alcohol and dried after the band is cut. Would keep the air layer intact through the winter and moist.

We wrap the layer in bubble wrap if freeze is forecast.

If you are really concerned one can use half strength 3% hydrogen peroxide (mix in water) once a month to knock down any pathogens from outside..

Cheers
DSD sends

 

[Shibui]

We wrap the layer in bubble wrap if freeze is forecast.

Some suburbs around Melbourne experience light frost a few night each winter but nothing that would bother a layer or a trident outdoors so I would not bother insulating any layers.
The only problems I have experienced with maples is when the soil is way too wet in winter or early Spring. I doubt there's any cause to worry about infection.
Even if your layers don't develop roots in the time you have, pot up the layers when you remove them. They should have produced callus by then and that's the biggest part of producing roots. The callused layers can be treated as cuttings and will often root pretty quick as the weather warms in Spring.

 

[AGentleman]

This is my 1st year growing trees and I'm really interested in learning how they grow in my environment.
It's rare that we get a crunchy grass strength frost here in the suburbs however my wife does wait til the last frost before planting her tomatoes each year.
That's amazing information about the callouses. I don't think I've heard anyone say that before (maybe Jelle on YouTube emphasised the importance of callousing but I didn't get it).
I'm going to throw caution to the wind and try some various air layering techniques this long weekend. And if the tree dies, it will only be the 2nd tree I've killed!
I think I'll buy a more established (starter) tree for next year so I can learn some other techniques and really think through what I do and what I want the tree to do.
Thank you Deep Sea Diver and Shibui for your advice and I'll let you know how the tree goes.
Greg

 

[AGentleman]

Over the long weekend, I started three air layers on my trident maple. Each layer has its own line of foliage above it.



However, I’ve noticed an issue with the first air layer. The leaves directly above this layer have started to yellow and wither, while the leaves at the top of the branch remain healthy. This could be due to the recent stretch of very dry weather and 30°C+ (90°F) days, or it might be the result of my approach.



This first air layer was a challenge that went beyond my current skill level. I attempted to place a disc just below the upper cut to encourage radial root growth—a technique inspired by a forum thread Sorce started years ago. Unfortunately, I exposed the bark-less trunk to direct sunlight for over an hour in the hot morning sun. On top of that, I chopped the sphagnum moss very finely, which I now suspect might not provide enough air for the roots to form. In hindsight, I should have re-watched some instructional YouTube videos beforehand rather than after the fact!



To address this, I plan to replace the finely chopped sphagnum moss with uncut moss. If it doesn’t look promising, I might remove the entire air layer and start over using the standard method. Since it’s only been a week, I doubt any roots have formed yet.

Although this is meant to be a learning experience and failure wouldn’t matter, I still really hope it works!
Greg

p.s. I re-read the thread just before posting this and realised that I have done the exact opposite of both the experienced people who responded. Shibui said wait until you see the roots and Deep Sea Diver said be intentional and every technique has its best timing. No disrespect intended just blinkered enthusiasm!

 

[Shibui]

I exposed the bark-less trunk to direct sunlight for over an hour in the hot morning sun.

This is actually encouraged when layering. Sun dries out any remaining cambium and helps reduce bridging. It should not affect the cambium under the remaining bark and that's where your new roots will come from.
The fine chopped sphagnum might pack tight enough to cause a problem but I doubt it. Chopped sphagnum is used because it's easier to remove after the roots develop. Make sure there's some drainage for excess water. Flooding the bag with too much water is definitely detrimental.

However, I’ve noticed an issue with the first air layer. The leaves directly above this layer have started to yellow and wither, while the leaves at the top of the branch remain healthy. This could be due to the recent stretch of very dry weather and 30°C+ (90°F) days, or it might be the result of my approach.

This is occasionally a problem with layers. Hopefully it's just the tree trying to regulate leaf cover with water availability and it will stabilise after dropping a few leaves.
Not sure how deep you went when removing the bark. Cutting deep into the wood below will sever the sap flow and stop water reaching the top of the tree. Sometimes it's just bad luck. I suspect we can get occasional infections in through the cuts we make for the layer.
Whatever the cause, I don't think there's anything you can do at this stage.

 

[AGentleman]

Straight after reading your advice, I removed the plastic bag of wet sphagnum moss that I had wrapped around the air-layering pot to prevent it from drying out. I now realise it might have stayed too wet. The pot has some pathetic little drainage holes that I poked into it but I’m sure it’ll get enough drainage from the whopping big crack in the bottom of the pot. I check the moss top layer regularly.



Thank you for reassuring me about the sun exposure on the trunk and the sick leaves. It seems the leaf die-off has stopped. They are shaded out by the upper leaves as well.

I've attached photos showing the cambium when it was partially stripped and when it was fully removed. I believe I removed enough, but since this is my first time attempting this, having this record will be useful for the future.



I'll update the thread again after I’ve chopped off the branches.

Thanks again for all the advice, Greg