Japanese maple - bad roots

[swraka]

So, I've finally gotten myself a JM. It's not much - a nursery stock Bloodgood, but I've always wanted a JM and better cultivar has been hard to find for me, especially in a bit larger size.

Anyway, there's a root situation.

I was thinking my first action should be a repot given it's a nursery stock and there are still remains of burlap and wire in a container. The only way of fixing those roots I can see would be to layer them off, but here I'm confused by the order and timing of operations. Can I layer now too or should I postpone that for next year? Also, how's root layering different from branch layering in timing? Can it be done on a single root at the time to minimize the risk?

 

[River's Edge]

So, I've finally gotten myself a JM. It's not much - a nursery stock Bloodgood, but I've always wanted a JM and better cultivar has been hard to find for me, especially in a bit larger size.

Anyway, there's a root situation.

I was thinking my first action should be a repot given it's a nursery stock and there are still remains of burlap and wire in a container. The only way of fixing those roots I can see would be to layer them off, but here I'm confused by the order and timing of operations. Can I layer now too or should I postpone that for next year? Also, how's root layering different from branch layering in timing? Can it be done on a single root at the time to minimize the risk?

Your decision should be based on the overall condition of the tree and the current state of the buds. The timing for air layer is typically spring with either just before bud opening or a bit later after the new leaves have hardened off.
If the tree is healthy it would make sense to begin the air layer this year. if you are unsure of the health I would strengthen the overall health and air layer next spring.
Because you do not intend to use the old root base in the long term I would only repot if it was absolutely necessary.
The air layer could be considered close to a ground layer if low enough down and surrounded by a pot with bonsai soil up to the desired level.
However it makes more sense to first assess the trunk and select the most desirable location for layering.
perhaps post picture of the trunk for further advice.

 

[swraka]

Tree is in good health. Plenty of buds, on old wood too, bunch of previous years growth, no dead branches, no signs of trouble. Buds have started opening.
To my untrained eye soil seems ok - it's not a typical nursery soil and is composed of bark, peat and clay I believe. I don't know what's deeper at the core though. Tree has been growing in this pot for at least a year or two.
I might not have used the proper term here, my intention is to keep the entire trunk and grow new roots - something like the photo attached. I'm also adding the full tree shot (~week ago) and current state of buds. Trunk is 5cm and overall height is about 60cm.

 

[sorce]

I'd move your line up to include that crotch.

Better chance for a good radial roots.

And that bit of flare you're gaining lower will be bettered by the layer anyway.

Sorce

 

[Shibui]

No difference in layering roots or branches. Ground layering just denotes that the layer in in the ground (pot) instead of a container further up the tree. Exactly the same initial technique is used but instead of wrapping in sphagnum and plastic just cover the area with good potting soil. If necessary add a ring to hold some more soil so the area is well covered.

I would have no problem with repotting and doing the layer in one operation for JM. In that case I would not cut old roots as hard as a normal repot, just rake out the old soil with minimum root removal before adding new potting soil. Fresh soil will make a big difference to the health and vigor of the tree which is also likely to have a positive impact on the layer making new roots.

 

[Bonsai Nut]

Whenever dealing with JM cultivars for landscape, in almost every case you will be dealing with a grafted tree. The first thing you need to look for when planning the future of the tree is: where is the graft?

If you look closely at your tree, you will find the graft junction. Everything above that point is bloodgood, everything below that point is generic green JM. In the case of your tree, you may even find some branches coming out below the graft, and when they bud out, they will have different leaves than the upper part of the tree.

Hard to tell from a single photo, but if I had to guess, this is where your graft scar is. Needless to say, if you are going to air-layer, you want it to be above the graft union.

 

[Forrestford]

ehhh bad vert but you get the idea. If it were mines I would opt for an airlayer higher up.

 

[River's Edge]

Whenever dealing with JM cultivars for landscape, in almost every case you will be dealing with a grafted tree. The first thing you need to look for when planning the future of the tree is: where is the graft?

If you look closely at your tree, you will find the graft junction. Everything above that point is bloodgood, everything below that point is generic green JM. In the case of your tree, you may even find some branches coming out below the graft, and when they bud out, they will have different leaves than the upper part of the tree.

Hard to tell from a single photo, but if I had to guess, this is where your graft scar is. Needless to say, if you are going to air-layer, you want it to be above the graft union.

View attachment 366509

You have received good advice with respect to the air layer, I would still recommend selecting a site for the best overall base and trunk line for design,rather than just the whole tree! Carefully done you could air layer off more than one section at the same time.
Here is an example. This is an acer palmatum Kihachijo with five air layers.
Note I left a branch or two below the lowest air layer, extra insurance to keep the base healthy and plant in the landscape or air layer at the very lowest point in the base next year!

 

[JonW]

I'd ground layer where the roots meet the base. Cut a ring of bark off of each root where it meets the base of the tree, make sure to remove all cambium, add rooting hormone where you cut at the base of the tree and replant it in bonsai soil. There is a youtube video of this technique on a maple, but I couldn't find it. I did it on a boxwood this year. You can keep the root flare, but grow a whole new set of radial roots without the risk of heavy root pruning.

 

[swraka]

Whew, that's a lot of a useful insight and perspectives, thank you guys you're amazing!

You gave me a lot to think about. Although now I know less than I knew before But at least it seems I can't go wrong since whatever I do there will be someone to agree with it.

I understand bottom part of the trunk isn't particularly interesting and layering it higher up will produce a higher quality tree in the long run. Especially if that's a graft. Haven't considered it because grafts are usually much more noticeable. Now that you mention it, you might be right. I can't see it clearly, but there is something funky going on in this region.
On the other hand I really like the proportions and size of the tree as it is.

I don't know, have to think about it some more.

 

[Shibui]

You gave me a lot to think about. Although now I know less than I knew before But at least it seems I can't go wrong since whatever I do there will be someone to agree with it.

Welcome to bonsai.
in my view the differences of opinion don't mean someone is right and someone else is wrong, just means there are usually several possible ways to achieve a result.

If a graft cannot be easily identified there is no problem. Some people seem to have a pathological hatred of anything grafted. There are many threads dealing with this topic. if it does not stand out it does not matter!

I don't know, have to think about it some more.

Best course of action is take some time and consider options. Much more productive than diving straight in and reducing your options without any idea.

good luck with the cogitations......

 

[Adair M]

You don’t have to layer above the graft. On your tree, if I wanted better roots, I would later down low, just as you originally planned,

Good luck with your tree!