Help with Japanese Maple

[Toshi]

I picked up this JM about 2 weeks ago and could use some advice. I don't plan to do anything to it for time being but water and let it grow and when the trunk is large enough in a few years I'll cut back to shohin size.

It has 2 main branches that are in a Y shape, they each run about 2ft in length. With regards to trunk thickening, should I let them both grow uninterrupted or is it better to keep 1 leader and cut the other?

My other question is about the soil, it's in really poor potting soil. It's pretty root-bound and the only way that I can effectively water the entire rootball is to submerge it in a bucket full of water. Would it be beneficial to slip pot at this point? Maybe 2/3 organic 1/3 inorganic? I was reading a few other threads that said to try and match the new soil to the current substrate otherwise you end up doing more harm than good.

Lastly, when I picked it up out of the pot to examine it I noticed mold at the underside of the root ball although I couldn't really get a good picture. Should I scrape away that bit of mold or treat it with something?

Other than that it's been growing nicely.
Thanks for reading.

 

[Dav4]

If this were mine, I might want to use that low branch on the right as the next section of trunk. With that said, I'd cut the right side of the Y section, which is shading out that lower branch, back to the main trunk and let the other side grow until it's served it's purpose of thickening the trunk. As far as the soil/mold issue is concerned, if you're going to slip pot now, use a similar soil type, like soil conditioner or potting soil. If you don't, it becomes much harder to water effectively. When you re-pot next spring, you can bare root the tree and get it into a soil of your choosing. Your current soil mix is heavy in organics and mold or fungal organisms will be in there living on the decaying organic matter, which is not something to be concerned about. Good luck!

 

[Toshi]

If this were mine, I might want to use that low branch on the right as the next section of trunk. With that said, I'd cut the right side of the Y section, which is shading out that lower branch, back to the main trunk and let the other side grow until it's served it's purpose of thickening the trunk. As far as the soil/mold issue is concerned, if you're going to slip pot now, use a similar soil type, like soil conditioner or potting soil. If you don't, it becomes much harder to water effectively. When you re-pot next spring, you can bare root the tree and get it into a soil of your choosing. Your current soil mix is heavy in organics and mold or fungal organisms will be in there living on the decaying organic matter, which is not something to be concerned about. Good luck!

10/10, very thorough and simple. I very much appreciate your feedback.

 

[Lorax7]

I picked up this JM about 2 weeks ago and could use some advice. I don't plan to do anything to it for time being but water and let it grow and when the trunk is large enough in a few years I'll cut back to shohin size.

It has 2 main branches that are in a Y shape, they each run about 2ft in length. With regards to trunk thickening, should I let them both grow uninterrupted or is it better to keep 1 leader and cut the other?

My other question is about the soil, it's in really poor potting soil. It's pretty root-bound and the only way that I can effectively water the entire rootball is to submerge it in a bucket full of water. Would it be beneficial to slip pot at this point? Maybe 2/3 organic 1/3 inorganic? I was reading a few other threads that said to try and match the new soil to the current substrate otherwise you end up doing more harm than good.

Lastly, when I picked it up out of the pot to examine it I noticed mold at the underside of the root ball although I couldn't really get a good picture. Should I scrape away that bit of mold or treat it with something?

Other than that it's been growing nicely.
Thanks for reading.


View attachment 194013View attachment 194014View attachment 194015

I would leave the 2 branches in the Y for now. When you do the trunk chop later, it will be below that point anyway, so I’d just let that part grow for now to help thicken the trunk below it.

I would not slip pot it. I would instead bare root it and trim the root ball to start developing a more shallow radial root system and repot it into a wider and more shallow pot than the one it’s in. Some people plant trees in the ground on top of a tile. That works too. My preference is to keep it in a pot so it’s on the bench and I don’t have to bend over to work on the trees. It’s perhaps a bit late for optimal growth to be doing a repot now, but I’ve repotted Japanese maples later than this before with no ill effects. They’re reasonably tough and can take it.

Soil mix is a controversial topic, so others will have very different opinions. I try to use mostly inorganic material (pumice, lava rock, akadama, gravel, oil dry) and just a little bit of organic material (pine bark) in my mix. Some people use no organic at all. Others use more. I usually sprinkle a bit of the original soil into the container when repotting just to get the mycorrhizae colony going, but just a sprinkling of the old soil. Don’t worry about preserving more. It’s not necessary. Also, sift your soil components to eliminate very fine particles. The really fine particles clog things up and don’t let the soil drain properly, so you don’t want them in your mix.

 

[namnhi]

I would leave the 2 branches in the Y for now. When you do the trunk chop later, it will be below that point anyway, so I’d just let that part grow for now to help thicken the trunk below it.

I would not slip pot it. I would instead bare root it and trim the root ball to start developing a more shallow radial root system and repot it into a wider and more shallow pot than the one it’s in. Some people plant trees in the ground on top of a tile. That works too. My preference is to keep it in a pot so it’s on the bench and I don’t have to bend over to work on the trees. It’s perhaps a bit late for optimal growth to be doing a repot now, but I’ve repotted Japanese maples later than this before with no ill effects. They’re reasonably tough and can take it.

Soil mix is a controversial topic, so others will have very different opinions. I try to use mostly inorganic material (pumice, lava rock, akadama, gravel, oil dry) and just a little bit of organic material (pine bark) in my mix. Some people use no organic at all. Others use more. I usually sprinkle a bit of the original soil into the container when repotting just to get the mycorrhizae colony going, but just a sprinkling of the old soil. Don’t worry about preserving more. It’s not necessary. Also, sift your soil components to eliminate very fine particles. The really fine particles clog things up and don’t let the soil drain properly, so you don’t want them in your mix.

Bareroot a tree when it has leaves like this is a risk no one should have to take. I think that is I'll advise. Let it grow now and do it right in the next optimal time for repot and trim which is late winter or early spring.

 

[Toshi]

I would leave the 2 branches in the Y for now. When you do the trunk chop later, it will be below that point anyway, so I’d just let that part grow for now to help thicken the trunk below it.

I would not slip pot it. I would instead bare root it and trim the root ball to start developing a more shallow radial root system and repot it into a wider and more shallow pot than the one it’s in. Some people plant trees in the ground on top of a tile. That works too. My preference is to keep it in a pot so it’s on the bench and I don’t have to bend over to work on the trees. It’s perhaps a bit late for optimal growth to be doing a repot now, but I’ve repotted Japanese maples later than this before with no ill effects. They’re reasonably tough and can take it.

Soil mix is a controversial topic, so others will have very different opinions. I try to use mostly inorganic material (pumice, lava rock, akadama, gravel, oil dry) and just a little bit of organic material (pine bark) in my mix. Some people use no organic at all. Others use more. I usually sprinkle a bit of the original soil into the container when repotting just to get the mycorrhizae colony going, but just a sprinkling of the old soil. Don’t worry about preserving more. It’s not necessary. Also, sift your soil components to eliminate very fine particles. The really fine particles clog things up and don’t let the soil drain properly, so you don’t want them in your mix.

Oof that sounds a bit cavalier for me, not sure I have the experience to root prune a maple this late in the season and keep it alive.

 

[_#1_]

I would not slip pot it. I would instead bare root it and trim the root ball to start developing a more shallow radial root system and repot it into a wider and more shallow pot than the one it’s in.

You do this to a tree that's growing full steam??? Can we see a sample of what you did, which tree, and when?

Now, this is start of my 3rd growing season and I still got a ton to learn in terms of proper horticulture, but I never heard of anyone doing any sort of root work on a fully growing maple. Up pot, sure. Let's not have the new guy take i'll advised chance to be left with a dead tree.

This has worked for me and it should work for you @Toshi since we're close. It should be OK to up pot now.

Loosen the very outer edge of rootball , so the roots can be expose to new soil.

Find a pot about an inch larger than original. That makes it half inch on each end.

I use 60/40 soil conditioner/potting soil. Sometimes I use 8822 instead of potting soil.

This should keep the tree stable till next spring when you can do a proper repot with root work.

 

[Lorax7]

Bareroot a tree when it has leaves like this is a risk no one should have to take. I think that is I'll advise. Let it grow now and do it right in the next optimal time for repot and trim which is late winter or early spring.

Here’s a Japanese maple that I bought from the garden center at a local grocery store, brought home, and repotted in the middle of July last year. I did a trunk chop and pruned a few other branches at the same time.

The second photo is the same tree today.

Would I recommend a repot for a highly developed tree that you’ve put years of development into at this time of year? No. But, for a nursery tree that you just acquired, I say go for it unless it’s an expensive variety that you paid big $$$ for. Between the risk of losing $20 to $30 by killing a nursery tree from being a bit aggressive vs. wasting a growing season because of being too conservative about working the tree, I’ll choose the former every time.

 

[Toshi]

Here’s a Japanese maple that I bought from the garden center at a local grocery store, brought home, and repotted in the middle of July last year. I did a trunk chop and pruned a few other branches at the same time.
View attachment 194034
The second photo is the same tree today.
View attachment 194038
Would I recommend a repot for a highly developed tree that you’ve put years of development into at this time of year? No. But, for a nursery tree that you just acquired, I say go for it unless it’s an expensive variety that you paid big $$$ for. Between the risk of losing $20 to $30 by killing a nursery tree from being a bit aggressive vs. wasting a growing season because of being too conservative about working the tree, I’ll choose the former every time.

That's really cool but I think I want to learn my way around the species first before attempting something like that. Maybe one day I'll be as brave as you :]

 

[Dav4]

Bare rooting a maple in late May is asking for trouble. Up pot as planned and do meaningful root work with little risk at the right time, which would be next spring just as the buds are pushing.

 

[_#1_]

Would I recommend a repot for a highly developed tree that you’ve put years of development into at this time of year? No. But, for a nursery tree that you just acquired, I say go for it unless it’s an expensive variety that you paid big $$$ for. Between the risk of losing $20 to $30 by killing a nursery tree from being a bit aggressive vs. wasting a growing season because of being too conservative about working the tree, I’ll choose the former every time.

Lol We can agree to disagree .

For someone new to this with little experience and limited number of stocks I think it's just better to learn best practice and go with what's safe (for the health of the tree). Even if the tree is $1.

Also it's best for the owner to see how the new tree respond to his/her micro environment before trying anything...

 

[Toshi]

Ok so found a 2gal pot at a nursery nearby, very lightly loosened some of the roots and filled with potting soil mixed with a little gravel. I also cut one of the 2 main branches back.

 

[M. Frary]

Excellent.
Glad to see you didn't go the other route. Barerooting a deciduous tree in full leaf is risky at best.

 

[Cable]

You can't train a dead tree. Bare rooting a JM in leaf is reckless. Can it survive? Sure! But that doesn't make it a good idea.

 

[Toshi]

Growing well so far. There are a couple of branches that are very sparse with foliage only at the tip of the branch. Would pruning those leaves translate into budding back along the branch or should I just leave them be?

 

[Toshi]

So i'm not sure what I did wrong but this tree hasn't put out any growth this whole summer. I haven't had any episodes of leaf dropping or brown/crispy leaves but what I did notice is that the tips of some of the stems are black, almost as if they've been seared with a lighter. I'm not sure if it's attributable to the fact that my balcony gets harsh sunlight all day as well as brutal winds or the really poor soil it's in but should I be concerned? Do you think this will impact its ability to successfully get through winter? Still looks healthy I think.

 

[Toshi]

Update - I cut this back hard in late March.

 

[Toshi]

Last week, buds started extending so I repotted into a plastic mica pot and shaved down the stump. Right now there's only a handful of buds, I hope that changes : /

 

[Nanuk]

Last week, buds started extending so I repotted into a plastic mica pot and shaved down the stump. Right now there's only a handful of buds, I hope that changes : /

View attachment 241778View attachment 241779View attachment 241780

I would cover the nebari with soil if it were mine.

 

[Toshi]

I would cover the nebari with soil if it were mine.

Why's that? Nebari was the last thing on my mind honestly I'm just thankful it survived. I have no idea what went wrong over the last year.