I recently posed the following challenge to the fine folks over at /r/bonsai.



This is a tree that someone recently asked me about. I came up with 6 hypothetical chop points and photoshopped them in. The second photo shows the pot that it’s in so you can get a sense for the roots. It’s in a larger pot than is at first obvious, with a smaller white collar on top filled with soil.

So here’s the game – assume I dropped this tree on your doorstep and you had to set it up well for the growing season. Please explain how you’d proceed and why. You can choose any of the 6 chop points I drew or none, but you have to explain your thought process.

SPOILER ARLERT: If you want to take a crack at it yourself before seeing our answers, don’t scroll past the two pictures until you’ve decided what you’d do and why.

Someone online asked my opinion on what to do next with this tree.

This is the pot it’s sitting in. It’s a larger pot, with a small white collar on top filled with soil.

Answers from some folks at /r/bonsai.

So that’s where it started, and I got a wide variety of answers. Here is a selection of them:

“Chop on 5.” When asked why, they changed to 4 in case of die back, with 3 if you really want to be safe. Fair enough.

“Air layer at 2 then cut down to 5.”

“Air layer at 2, cut at 3 or 5. One branch as the new top, the other as first branch.” So two votes for air layer at 2.

“Air layer 3 when leaves harden off (grab lots of trunk). Chop 4 the following winter, left upright branch at 5 is the new leader.” I think the air layer would get in the way of this plan. Air layering at 2 would give you more room.

“Expose the nebari, slip-pot into a large grow box on a slate. Let it grow out this year then chop the end of next winter at 4. Use the right branch below for the new leader unless something better develops. Clean up the chop the next spring, develop branches that summer and repot the following spring into a good pot.” I like the long term thinking here.

“6, of course. No guts no glory.” From Jerry, my fellow moderator. This would almost certainly yield the best trunk if it worked out.

Some critique of some of the guessed plans

I’ll get into my own thoughts on specific actions I would take below, but a few important points I’d like to hit here to critique some of the suggested plans:

Most took the question quite literally, and just named one of the chop points. Most of the reasons were artistic, trunk-building reasons. Here’s my take on that. There’s no way in hell I’d chop this tree for artistic purposes without evaluating the roots first, and correcting any problems. Most did not mention that, and it’s important to think of the tree as a holistic system.

Those who called for air layering, be mindful of timing. I’m not a layering expert myself (something I plan on working on soon), but it’s my understanding that it works much, much better if the leaves are already grown in. For those saying to start the layer now, in this state, just be mindful of researching seasonal timing of activities before just diving in, and also the state of the tree you’re about to do work on. You wouldn’t want to air layer a weak tree. btw, this thread from Bonsai Nut is the best air layering guide I’ve seen to date: https://www.bonsainut.com/threads/the-science-of-air-layering.27034/

One other thought on air layering. Multiple people said they’d air layer at point 2. While one could certainly do this, a key reason for air layering in the first place is to start with a trunk that looks like a tree where you can immediately start working on branches. If you layered at point 2, you’d have a trunk that required years of root development just to get it to the point where it was ready for another chop to build taper. There are much faster ways to get there than this.

Also, someone else said they’d air layer now, and then after removing it this season, they’d chop further down the trunk later this season. If one were to do an air layer followed by a chop, my suggestion would be to let the base tree recover for a year after the air layer is complete, and see how the base tree does next season before attempting to chop further.

Evaluating the situation

Ok, so here’s my take. First, let’s start with an evaluation of what we see here.

It doesn’t look like it was growing particularly strongly last season. The branches it has don’t really have any ramification, and the total height of the tree is about 3 feet. There isn’t much going on past the top of the picture.

According to the owner, it’s been in that pot for quite some time. For a tree that’s been in that pot for a long time, there just doesn’t seem to be a lot of branch growth to show for it. This makes me think that it’s struggling or in decline.

The pot set up is a bit odd. I see things like that done for ground layering, but from a conversation with the tree’s owner, I don’t think that’s what’s going on here. I think it’s literally a collar filled with soil.

I’m extremely curious about what’s going on both underneath that white collar, and also in the pot itself. That will determine the correct path forward.

Given the state of the tree, the roots are definitely my number one point of focus.

My plan for the tree

So first, I’ll say that pretty much everyone’s plans were plausible, at least in the long term. However, I think most of the suggested plans would not have ended the way the person thinks, or would at least have been unnecessarily risky.

Here’s why. Like I mentioned above, this tree shows signs of struggling, and you don’t want to do massive traumatic work to a struggling tree. That’s a good way to kill the tree or have your plan fail.

Here’s where I’d go with it. My plan would be to first set the tree up for success.

First, I’d need to see what’s under that white collar. There are a few possibilities here:

1) If it’s full of roots, one option would be to treat it like a ground layer and saw it off right now. For me to do that on a tree of unknown health, the root system inside that collar would have to be spectacular. The current top of the tree doesn’t make me think that’s the case.

2) If it’s devoid of roots, I’d probably remove it and all that soil in order to get a view of where the actual root line is. Then I’d plan my next moves. There are two likely scenarios in this case – either you’d find something particularly interesting to chop back to, or you’d find a great spot that was particularly interesting to ground layer and build a new set of roots.

3) If it were somewhere in between, and I liked what the roots were doing so far, I might re-set the system to continue encouraging roots in that location. But if there was something more interesting below the upper root line, I might just cut them all off and rely on the root system in the lower, larger pot.

So what to do next is a big fat “It depends”. But in each case, I’d be far more likely to want to get a strong root system going at my desired trunk line.

I’d want to get this growing strongly before any big chops.

Here’s what I ideally like my root systems to look like (dense and full of roots):

Here’s what I like to see with raw stock. Tree in the middle of the pot, surrounded by a dense root ball.

The roots were so dense I needed a saw to cut through them,



The remaining root ball is dense and full of feeder roots.

I did a little more clean up with a root rake to prep the root ball for the training pot.

I like to go from a nursery pot to a large training pot, and let the tree run at this scale for a while. It will be in this pot for at least a few years while I refine the major branches.

Now, to map this onto the maple scenario. Before doing any major work on the maple, I’d at least want the root ball in a similar state to how this birch looked before I repotted it. And if I didn’t do it then, I’d want it to be in the state that the birch will be in 2-3 years after recovering from the re-potting work shown here. That might even be preferable given how root bound this one was.

In either case, I’d want to be working from a known good root system that was generating strong growth each season.

So big picture,

Get the roots squared away, find your desired soil line.

Build a solid root system below that. Build a strong root ball. Do whatever is necessary to get you there, probably 2-3 years of development time.

If a big chop is needed at that point, then might be a decent time to do it. I’d be inclined to pick the lowest rational point for the chop. Either point 6 on the diagram, or maybe even lower depending on what’s under that white collar.

I’d keep it in a grow box or decent size training pot when doing the chop.

Re-build the trunk from there. I’d keep it in a training pot or grow box for most of this process, probably 8-10 years with some light re-pots along the way.

In this way, you can safely guide the tree towards the desired result rather than just try and brute force it. It’s could easily take 10-15 years of work to get this into decent shape and heading towards a bonsai pot, but it could potentially be quite good pre-bonsai material at that point.

And one last point. When doing the root work, I may very well cut back to point 1 on the original diagram. That’s up high enough that it’s extremely unlikely to affect the tree, but sets the scale nicely so the tree redirects growth to areas that are more interesting than wasting time on things we absolutely do not need.

The reason I’d choose point 1 is because I’d want every single other little branch in that picture to contribute to the recovery of the root ball. Cutting back much further than that would probably be counter-productive at this point.

Please let me know if you like this format. I enjoyed the process of writing this one, and am likely to do a series of these.