Too late to get this JM in better soil?

[Lorax7]

I realize that nursery practices in the US are not completely the same as in Europe. But here in the Netherlands, nursery plants need to be absolutely of the highest quality, or else no one will buy them as the competition does have superior plants.
On top of that, the soil or substrate cost will not really be relevant compared to costs for labour, infrastructure, transport, fertilizer, etc. Whatever type of dirt you use, it is going to be dirt cheap. They will all be cheap. And whether you put pine bark, lava rock, perlite, peat, sharp sand or whatever in a bag, that all doesn't really matter. The main cost will be for putting that stuff inside a bag inside a factory and then shipping it to the customer. Not the cost of what is inside.
The idea that nurseries are using inferior soil because it is cheap so they can make more profit on lower quality plants just doesn't make sense. If it was better for them to use substrate, they would. If they needed more drainage to grow a better maple, they would have added lava rock.

Doesn't mean a tree can't get too wet in a nursery pot. Some places indeed get a ton of rain, much more than what they would get when irrigated inside a hoop house. And overpotting is a problem.
But in general, for growing normal plants aka broadleaf evergreens, fresh peat or pine bark is superior to substrate or lava rock when you grow outdoors. When you have a more controlled environment with fertigation, then you could use substrate/hydroponics. Cacti and some conifers that need way more drainage are also different of course.
Doesn't mean you can't mix in substrate when you grow JMs in nursery pots. It all depends on your climate and your watering regime. But when you get a nursery plant in fresh soil, that soil is generally good. There's no reason to go to 'bonsai soil' aka substrate.
The thing to worry about with a nursery plant/tree is if it has already been way too long inside that pot and it ought to have ben repotted already. That definitely doesn't seem the case here. Whether this specific maple is over-potted, I'll leave that to the JM experts.


Bonsai is entirely different. The issue is the very shallow pot and the limited amount of roots. Which requires daily watering and even morning and afternoon watering in summer. Which means that using soil, it would get too wet. The margin of error is way smaller because of the limited root volume. So you use fast-draining substrate and you water all the time.

I’m not saying the soil nurseries use is somehow substandard. It’s perfectly fine for the growing conditions of the nursery where they put their trees inside a hoop house when the cold and wet fall arrives (if the tree is unsold, that is — they typically have deep discounts on trees in the fall, as they would rather sell them to avoid the labor and storage costs). Nursery soil mix is also just fine for the overwhelming majority of their customers who aren’t going to keep the tree in a pot for more than a couple weeks at most before planting in the ground.

I am saying that nursery mix sucks as a substrate for growing bonsai in a cold, wet climate (unless you have a cold greenhouse where you can keep the tree out of the rain).

 

[leatherback]

I would not repot but instead airlayer it straight in there. In 8 weeks you have it layered and you move it to substrate.

 

[Shibui]

Double post - see below

 

[Shibui]

Seeing you asked directly I'm with @Dav4 I've also repotted maples with leaves further along than this one appears to be so it is possible, at least here and under my conditions. The leaves at this stage are not using excessive amounts of water so there's time for the roots to recover before maximum water needs in a few weeks.
As Dav4 said, Try to minimise root reduction if possible. You don't want to keep the original root stock roots so no need to go all out reducing them. Just comb out as much of the old soil as you feel necessary with minimal root reduction and replace with fresh mix.

Reading the replies so far it seems you are set on changing the soil and just looking for confirmation. As someone else said, there is always a risk v reward continuum. You'll need to decide if the risk is worth the perceived rewards.
Those that are advocating let it be and get on with the layer this spring are correct. The soil it is in will probably get the tree through the summer in most areas with a slight chance of root problems if watering is excessive.
You know your watering regime and local weather better than any of us so are in a better position to make the decision on the chances of root problems and whether the slight risk associated with repotting now is worth the reward. I think the risk is slight but please don't blame me if it doesn't work out.

If you do decide to go ahead, some follow up to show what happened would be great.

 

[The Warm Canuck]

I would not repot but instead airlayer it straight in there. In 8 weeks you have it layered and you move it to substrate.

Seeing you asked directly I'm with @Dav4 I've also repotted maples with leaves further along than this one appears to be so it is possible, at least here and under my conditions. The leaves at this stage are not using excessive amounts of water so there's time for the roots to recover before maximum water needs in a few weeks.
As Dav4 said, Try to minimise root reduction if possible. You don't want to keep the original root stock roots so no need to go all out reducing them. Just comb out as much of the old soil as you feel necessary with minimal root reduction and replace with fresh mix.

Reading the replies so far it seems you are set on changing the soil and just looking for confirmation. As someone else said, there is always a risk v reward continuum. You'll need to decide if the risk is worth the perceived rewards.
Those that are advocating let it be and get on with the layer this spring are correct. The soil it is in will probably get the tree through the summer in most areas with a slight chance of root problems if watering is excessive.
You know your watering regime and local weather better than any of us so are in a better position to make the decision on the chances of root problems and whether the slight risk associated with repotting now is worth the reward. I think the risk is slight but please don't blame me if it doesn't work out.

If you do decide to go ahead, some follow up to show what happened would be great.

No repot is needed.

Concur with @River's Edge. Layer the tree.. Not that tiny.

Keep in the pot as is and air layer the tree above the graft after the leaves harden off. The rootstock on the graft is already swelling and will only get larger,

Actually a ground layer job. This will give the tree plenty of time to push new roots before fall. Whether or not the tree is separated this fall is a personal choice, but the tree could easily winter over with the layer on.

Doing so will save a year, getting this tree’s nebari started in the right direction. Once separated think about putting the tree in a box.

Think about making some minor reductions in the top hamper to get started on an effort to develop taper in key branches. These can
save one the trouble

Btw if you desire specific answers to questions, simple PM these folks. Start by hitting the envelope icon on top of the page.

cheers
DSD sends

I've never air layered such a small tree. That's why I want to get it into a better soil to give it a few years of growth before layering. I've been under the impression that it's better to have a stem bigger than 1" to layer.

How would you guys approach this layer?

The tree splits right at the graft, so I don't think I can get a air layer under the fork. Would you just layer the branch to the left? It's only about 3/8" thick? i guess if it was unsuccessful, I'd still have the other branch.

I've never tried a ground layer, maybe that small space under the fork? The distance from the graft to the bottom of the fork is about 1/2". Wouldn't bridging be likely?

Never tried the tourniquet method, would this be a good candidate? right at the graft point?

 

[Shibui]

Of course you can layer under that fork. No problem including some of the stock where you want roots. It may even root quicker. Any graft mark will be swallowed up in the new root base and will never be seen.
Even if you want to produce roots right at or above the graft you just remove the bark from the stock below. My guess is there's likely to be a few more inches of stock below soil level before you hit the roots so plenty of space to get a layer.
Layers this low don't need to be air layer bags of sphagnum. Ground layer uses the same technique but just buried by raising soil level to cover the layer area. You have plenty of freeboard in the pot so don't even need to raise the sides of the pot for this one.

 

[The Warm Canuck]

Of course you can layer under that fork. No problem including some of the stock where you want roots. It may even root quicker. Any graft mark will be swallowed up in the new root base and will never be seen.
Even if you want to produce roots right at or above the graft you just remove the bark from the stock below. My guess is there's likely to be a few more inches of stock below soil level before you hit the roots so plenty of space to get a layer.
Layers this low don't need to be air layer bags of sphagnum. Ground layer uses the same technique but just buried by raising soil level to cover the layer area. You have plenty of freeboard in the pot so don't even need to raise the sides of the pot for this one.

Oh this seems like a no brainer than.

Do you ever use a wire tourniquet?

 

[Dav4]

Oh this seems like a no brainer than.

Do you ever use a wire tourniquet?

I would ground layer this plant right at the graft union, scraping away all the bark and cambium down at least one inch. Apply rooting hormone above the ring of exposed wood and add more soil until the sight of the layer is covered by at least an inch. I’ve never used a wire and have been 100% successful layering Japanese maples this way.

 

[Glaucus]

I am saying that nursery mix sucks as a substrate for growing bonsai in a cold, wet climate (unless you have a cold greenhouse where you can keep the tree out of the rain).

It is not a bonsai.

 

[dbonsaiw]

FWIW, I've kept many a JM in Home Depot soil for at least a year with no issues. Went to HD the other day for a tool and, of course, came home with a bloodgood. I was out of bonsai soil, so I just worked the roots and repotted it back in a grow box (14X14X5") in the same pine bark soil. Maybe I should be, but I am not concerned. It just won't get watered as often as the other trees.

 

[The Warm Canuck]

FWIW, I've kept many a JM in Home Depot soil for at least a year with no issues. Went to HD the other day for a tool and, of course, came home with a bloodgood. I was out of bonsai soil, so I just worked the roots and repotted it back in a grow box (14X14X5") in the same pine bark soil. Maybe I should be, but I am not concerned. It just won't get watered as often as the other trees.

I'm not saying the tree is going to die, just the soil isn't ideal. You seem to confirm this notion, as you intended to plant it in Bonsai soil, if you had it on hand. However, you still planted it in a wider and shallower pot, which I also agree is more beneficial.

 

[dbonsaiw]

just the soil isn't ideal.

Agree 100%. To me, there's no question that bonsai soil will provide for the best development, and I'll use that even in larger grow boxes. But it gets rather expensive.

 

[The Warm Canuck]

Agree 100%. To me, there's no question that bonsai soil will provide for the best development, and I'll use that even in larger grow boxes. But it gets rather expensive.

I'm not using Bonsai soil perse but 50% perlite / 50% pro-mix HP. Like you said Bonsai soil can get expensive, especially in grow box's. I do use a light top layer of bonsai soil, to keep the perlite from blowing away.

 

[Shibui]

Do you ever use a wire tourniquet?

I have used wire torniquet for layering but that can be used several different ways.
1. Just tie a wire tightly around the bark and cover the area with rooting media. As the trunk thickens the wire bites in and produces callus which will eventually form roots. This method is slow and probably developed for those who are scared of taking off bark. May possibly be useful for species that do not root or layer easily?
2. Remove a strip of bark and tie wire tight around the wood in the debarked space. The wire appears to prevent new cambium 'bridging' the gap. The original version of this method that I saw removed just a very narrow strip of bark - just wide enough to take the wire. From all accounts this works well. I've only used it a couple of times many years ago and I can't recall the outcomes.
3. Some people add a wire torniquet to a normal, wide layer. Best application would seem to be right up close to the top of the cut. I guess the aim is to prevent possible bridging. Some pics I've seen look like wire has been applied randomly as an afterthought.

Any torniquet is only really useful where the trunk is smoothly rounded as the wire skips over any hollow areas, thus allowing continued circulation. In the narrow strip method mentioned above the wire was hammered into the groove to make sure it was in close contact all round the trunk. That would seem to be the best use of wire in layering IMHO

 

[The Warm Canuck]

Scraped the bark and wired some branches to give it some "bones". I'll add some soil in a few days, going to give it a few days to dry out, (I'm paranoid of bridging..lol).

 

[The Warm Canuck]

How much soil should be covering the top cambium cut? 1-1/2" ish?

 

[Dav4]

How much soil should be covering the top cambium cut? 1-1/2" ish?

I'd add soil until it's slightly higher than where the first branch leaves the main trunk.