Is this rookie mistake going to cost me an Arakawa/Koto Hime?

[Bonsai Noodles]

Hey, all!

I humbly come to thee seeking advice on how to salvage this situation I've single-handedly put myself in.

After catching the Arakawa-itch, I bought some nursery stock from Bill V the Great. He also had his "trademark" Koto Hime, so I couldn't resist. But I miscalculated since the two trees arrived pot-less — in wrapped root balls basically (you can see the pictures below).

So I decided to rush to the nearest Home Depot and buy some nursery pots. But here's the first screw up... I think I might've bought nursery pots that are way too big for the trees. They seem too deep, and I'm pretty scared the trees won't drain properly now. I did make sure to use well-draining substrate (about 1:1:1 Akadama : Lava : Pumice). Hopefully, it drains well enough? I threw in some sphagnum moss to encourage root growth, but I do fear that would increase the water-retention too much. To pot again or not? I might've screwed up too much already...

In general, I know I shouldn't re-pot past August... Alas, it's September! So I semi-slip-potted them (I loosened up the root balls, but I did not cut any roots). Do you think the trees have good odds at establishing roots in their new soil to survive this winter? I'm scared I may have disturbed the root system too much though... I was a bit aggressive with using chopsticks when trying to loosen the dense root balls and filling soil gaps.

Hopefully, this is enough to keep these two beautiful little fellas alive? Anything else I can do to make sure they make it past this winter? I heard arborists use root hormone when transplanting trees. Thoughts on that? Or should I just leave them alone...?

Thanks for the help!


Edit: I live in Minneapolis, MN. So winter temperatures come as soon as late October. Yikes!

 

[BonsaiDTLA]

The trees look okay currently, just be careful with watering.

Remember that the inner root ball could dry out while the outer parts of the soil and pot remain wet. If its well draining soil, it should be okay though.

I don't think there was a need to use root hormones in your case so don't worry too much

 

[Woocash]

I am FAR from an expert, but if you cut no roots then what is the harm in a slip pot? This really is a question more than a statement. I would love to know if there is any physiological reason why a tree should suffer from this procedure at this time of year. I mean, why would they be sent out potless if they were not meant to be potted up? I reckon you’ll be fine.

 

[Bonsai Noodles]

The trees look okay currently, just be careful with watering.

Remember that the inner root ball could dry out while the outer parts of the soil and pot remain wet. If its well draining soil, it should be okay though.

I don't think there was a need to use root hormones in your case so don't worry too much

Good to hear! I'll definitely keep this in mind. And I won't use root hormone

I am FAR from an expert, but if you cut no roots then what is the harm in a slip pot? This really is a question more than a statement. I would love to know if there is any physiological reason why a tree should suffer from this procedure at this time of year. I mean, why would they be sent out potless if they were not meant to be potted up? I reckon you’ll be fine.

Oo, that's a bit relieving to hear. I guess, like quite a lot of things, there's almost a spectrum? This could also be a noobie way of looking at things.

But when I imagine the difference between slip-potting and repotting, I think there's an in-between where you don't root prune as much or do as much of a "clean new slate" sort of repotting. I think what I did falls somewhere toward the slip-potting end of the spectrum, where I tried to not disturb the roots too much, but all my procedures might've severed some connections of the fine roots to the vascular system. I'm actually very curious about fall season plant physiology actually. We know that trees tend not to shoot out a new flush in the fall (growing stops around August, from what I've seen with my landscape trees and even this year with my new bonsai-in-training trees), so is a lot of their growth just focused on roots?

In any case, thanks for the answer!

 

[Leo in N E Illinois]

Your trees will be fine.

You used a well draining mix, the Akadama, Perlite & Lava is a good blend. Perhaps a touch dry for maples, but you added sphagnum, so that will take care of that. Too much sphagnum is bad, but we will assume you got it close enough.

You should be able to repot in late winter, early spring if you really feel the need to do so, but personally, I would limp them along as is for 18 months and repot in late winter or early spring 2022.

@Woocash - slip potting is often touted as being "totally harmless". This is false. any movement or shifting of the roots, even flexing of the plastic pot or grow bag if you are using grow bags, this flexing can break fine roots. Most of water and nutrient absorption is done by the root tips and root hairs. Somewhere in the 70% to 90% range is done by this relatively small amount of tissue. The older, more sturdy parts of the roots really absorb very little, compared to the fine tips and hairs. Disturbing the roots of a tree is the most traumatic thing you can do to a tree. Wiring and pruning are less traumatic. The tree is adapted to wind and insect damage. The tree is NOT adapted to being lifted out of the ground and having its roots messed around with.

So that said, if everything goes well "slip potting" might only be "mostly harmless" if everything goes perfect. Much more typical, sections of the soil mass might break away, tearing off large amounts of the finest roots. Trees get dropped, jostled or handled too roughly in the process, or worse yet the root tips dry out during "slip potting". You might not even be aware of how much damage you have done.

So ALWAYS, count the disturbance of "slip potting" as being as bad for a tree as regular repotting. If your tree is on a cycle of only repot once every 2 years or once every 5 years, "slip potting" absolutely counts as a "Full Repotting" and resets the timer on recovery required for different techniques.

WIth seedlings and young plants, often you can get away with "slip potting", but once a tree is beyond the seedling stage it is very risky to think slip potting does no harm. With trees that are sensitive about root disturbance, slip potting and then too soon doing a proper repotting can lead to death.

So do not "slip pot" if at all possible. Do a proper repotting, and do your nebari work and then allow sufficient time for recovery. Repotting trees too often is one of the major mistakes we do with our trees. I has taken me years to realize that repotting too often is a serious problem.

 

[Clicio]

With trees that are sensitive about root disturbance, slip potting and then too soon doing a proper repotting can lead to death.
So do not "slip pot" if at all possible.

This is soooooo true!
But one has to learn always by the hard, sad way...

 

[Woocash]

Your trees will be fine.

You used a well draining mix, the Akadama, Perlite & Lava is a good blend. Perhaps a touch dry for maples, but you added sphagnum, so that will take care of that. Too much sphagnum is bad, but we will assume you got it close enough.

You should be able to repot in late winter, early spring if you really feel the need to do so, but personally, I would limp them along as is for 18 months and repot in late winter or early spring 2022.

@Woocash - slip potting is often touted as being "totally harmless". This is false. any movement or shifting of the roots, even flexing of the plastic pot or grow bag if you are using grow bags, this flexing can break fine roots. Most of water and nutrient absorption is done by the root tips and root hairs. Somewhere in the 70% to 90% range is done by this relatively small amount of tissue. The older, more sturdy parts of the roots really absorb very little, compared to the fine tips and hairs. Disturbing the roots of a tree is the most traumatic thing you can do to a tree. Wiring and pruning are less traumatic. The tree is adapted to wind and insect damage. The tree is NOT adapted to being lifted out of the ground and having its roots messed around with.

So that said, if everything goes well "slip potting" might only be "mostly harmless" if everything goes perfect. Much more typical, sections of the soil mass might break away, tearing off large amounts of the finest roots. Trees get dropped, jostled or handled too roughly in the process, or worse yet the root tips dry out during "slip potting". You might not even be aware of how much damage you have done.

So ALWAYS, count the disturbance of "slip potting" as being as bad for a tree as regular repotting. If your tree is on a cycle of only repot once every 2 years or once every 5 years, "slip potting" absolutely counts as a "Full Repotting" and resets the timer on recovery required for different techniques.

WIth seedlings and young plants, often you can get away with "slip potting", but once a tree is beyond the seedling stage it is very risky to think slip potting does no harm. With trees that are sensitive about root disturbance, slip potting and then too soon doing a proper repotting can lead to death.

So do not "slip pot" if at all possible. Do a proper repotting, and do your nebari work and then allow sufficient time for recovery. Repotting trees too often is one of the major mistakes we do with our trees. I has taken me years to realize that repotting too often is a serious problem.

Well there we have it. I assumed that only the outside roots would be adversely affected and being such a small percentage of the overall root mass it wouldn't make much difference. Shows what I know! Thanks.

I imagine climate must make quite a difference in this regard when it comes to timings then. Being from Minnesota, I guess the OP would be offering winter protection anyway, but in milder climes this would be less of an issue? I have obviously noticed the post midsummer growth spurt and assumed that the roots will be in active growth as well so thought now would actually be quite a good time of year for such procedures, if necessary. I’d be wary of extensive root work now, but even minimal disturbance isn’t quite so minimal. Interesting.

 

[Bonsai Noodles]

Your trees will be fine.

You used a well draining mix, the Akadama, Perlite & Lava is a good blend. Perhaps a touch dry for maples, but you added sphagnum, so that will take care of that. Too much sphagnum is bad, but we will assume you got it close enough.

You should be able to repot in late winter, early spring if you really feel the need to do so, but personally, I would limp them along as is for 18 months and repot in late winter or early spring 2022.

@Woocash - slip potting is often touted as being "totally harmless". This is false. any movement or shifting of the roots, even flexing of the plastic pot or grow bag if you are using grow bags, this flexing can break fine roots. Most of water and nutrient absorption is done by the root tips and root hairs. Somewhere in the 70% to 90% range is done by this relatively small amount of tissue. The older, more sturdy parts of the roots really absorb very little, compared to the fine tips and hairs. Disturbing the roots of a tree is the most traumatic thing you can do to a tree. Wiring and pruning are less traumatic. The tree is adapted to wind and insect damage. The tree is NOT adapted to being lifted out of the ground and having its roots messed around with.

So that said, if everything goes well "slip potting" might only be "mostly harmless" if everything goes perfect. Much more typical, sections of the soil mass might break away, tearing off large amounts of the finest roots. Trees get dropped, jostled or handled too roughly in the process, or worse yet the root tips dry out during "slip potting". You might not even be aware of how much damage you have done.

So ALWAYS, count the disturbance of "slip potting" as being as bad for a tree as regular repotting. If your tree is on a cycle of only repot once every 2 years or once every 5 years, "slip potting" absolutely counts as a "Full Repotting" and resets the timer on recovery required for different techniques.

WIth seedlings and young plants, often you can get away with "slip potting", but once a tree is beyond the seedling stage it is very risky to think slip potting does no harm. With trees that are sensitive about root disturbance, slip potting and then too soon doing a proper repotting can lead to death.

So do not "slip pot" if at all possible. Do a proper repotting, and do your nebari work and then allow sufficient time for recovery. Repotting trees too often is one of the major mistakes we do with our trees. I has taken me years to realize that repotting too often is a serious problem.

What an informative post! Thanks for sharing. This should be a "words of wisdom" thread of its own.

 

[MrWunderful]

I would have gone straight akadama if you are keeping these in bay area (Not sure how it acts in MN). And the trees being From Bill V, are going to do better in a slip pot than a nursery tree from Lowes- I still wouldnt slip pot myself but you didnt have a choice.
Just give them all of next year to recover and set the roots/structure following year.

 

[Bonsai Noodles]

I would have gone straight akadama if you are keeping these in bay area (Not sure how it acts in MN). And the trees being From Bill V, are going to do better in a slip pot than a nursery tree from Lowes- I still wouldnt slip pot myself but you didnt have a choice.
Just give them all of next year to recover and set the roots/structure following year.

This one's definitely staying in MN. I'm at that stage in my life where I haven't really settled down in one place yet — going back and forth for family/professional purposes. With the really low temperatures in MN, I do think Akadama might break down more readily — hence the decision to keep harder inorganics in my soil mix. But I'm still quite a noob and in my experimenting stages of bonsai raising.

In any case, will heed this advice!

 

[Woocash]

Good to hear! I'll definitely keep this in mind. And I won't use root hormone



Oo, that's a bit relieving to hear. I guess, like quite a lot of things, there's almost a spectrum? This could also be a noobie way of looking at things.

But when I imagine the difference between slip-potting and repotting, I think there's an in-between where you don't root prune as much or do as much of a "clean new slate" sort of repotting. I think what I did falls somewhere toward the slip-potting end of the spectrum, where I tried to not disturb the roots too much, but all my procedures might've severed some connections of the fine roots to the vascular system. I'm actually very curious about fall season plant physiology actually. We know that trees tend not to shoot out a new flush in the fall (growing stops around August, from what I've seen with my landscape trees and even this year with my new bonsai-in-training trees), so is a lot of their growth just focused on roots?

In any case, thanks for the answer!

No problem. I think it’s very easy to overthink things as a noob. I know I do! Nothing beats experience, but sometimes you have to think even if a pro throws you a curve ball, you still got to take a swing right?...

 

[Shibui]

I have to disagree with much of @Leo in N E Illinois assertions.

The tree is adapted to wind and insect damage. The tree is NOT adapted to being lifted out of the ground and having its roots messed around with.

While trees are not adapted to being out of the ground they have had to adapt to root loss. Even though we don't see it there is a constant war going on under the ground as roots compete for territory. Animals both small and large eat living roots and inadvertently break them as they burrow through the soil. Fungi and bacteria invade roots and kill sections. Dry conditions can kill some roots. Saturated soil can also temporarily kill roots. In some places fire and other extreme events kill off some of the roots.
Plants have developed mechanisms to cope with these ongoing traumas. They shed sections of damaged root. They stop growing in some areas and grow more in other areas. trees can survive the loss of some foliage. They can also survive loss of some of the root system. How many trees have blown over in storms or in wet weather ripping out half of the roots or even more but then continue to grow as a raft, sustained by the remaining few roots while new roots grow and develop. Many of these trees go on to live long lives after such a loss.
I'll also take issue with

So ALWAYS, count the disturbance of "slip potting" as being as bad for a tree as regular repotting.

I contend that regular repotting is not actually traumatic for trees. My bonsai almost always grow far better in the season following repotting. The proliferation of new roots and fresh mix enables more, healthier growth which gradually declines until the next repot. Most people are so convinced that root pruning is bad they refuse to see the evidence right in front of their eyes.
Slip potting, when done correctly, is just one possible tool in our bonsai arsenal. Light disturbance of a tight root ball so there is no barrier between old optimizes slip potting and eliminates many of the problems that can occur. The few roots that are damaged are quickly replaced and the tree almost always has reserves to cope with the temporary loss.

I think I might've bought nursery pots that are way too big for the trees. They seem too deep, and I'm pretty scared the trees won't drain properly now

Pots that are way too big can cause problems but there's a difference between 'too big' and 'deep'. Deeper pots actually drain far better than shallow pots. We see in general nursery practice that growers can get away with growing plants in all sorts of potting soil that would horrify a bonsai grower. They are able to do that because of the deeper pots. The shallower the pot the more critical drainage becomes. There is so much rubbish about now telling us that shallow trays are vital and deeper pots are bad. Not true, even from a bonsai perspective. Shallow training pots require very good cultural practices. Deeper pots will usually give better growth and development with less effort.

I'd be confident the trees posted will do fine. I am not familiar enough with your cold winters to know the full ramifications of that but roots do regrow and develop very quickly through the growing season - far more than those who are convinced that root reduction is traumatic can appreciate.
I would follow this slip pot with a full and decisive root prune in spring to check and balance the main lateral roots to set nebari development on the right track.

 

[amcoffeegirl]

I have one that I got this spring from Matt O. He says they grow like weeds. His climate may be different. I had roots growing out of the bottom of his pot so I did a slip pot in June, in Iowa. It did recover well.
Got a bit sunburned on the new growth but overall I can’t complain.
This is when I got it and today.

 

[Bonsai Noodles]

I have to disagree with much of @Leo in N E Illinois assertions.

While trees are not adapted to being out of the ground they have had to adapt to root loss. Even though we don't see it there is a constant war going on under the ground as roots compete for territory. Animals both small and large eat living roots and inadvertently break them as they burrow through the soil. Fungi and bacteria invade roots and kill sections. Dry conditions can kill some roots. Saturated soil can also temporarily kill roots. In some places fire and other extreme events kill off some of the roots.
Plants have developed mechanisms to cope with these ongoing traumas. They shed sections of damaged root. They stop growing in some areas and grow more in other areas. trees can survive the loss of some foliage. They can also survive loss of some of the root system. How many trees have blown over in storms or in wet weather ripping out half of the roots or even more but then continue to grow as a raft, sustained by the remaining few roots while new roots grow and develop. Many of these trees go on to live long lives after such a loss.
I'll also take issue with

I contend that regular repotting is not actually traumatic for trees. My bonsai almost always grow far better in the season following repotting. The proliferation of new roots and fresh mix enables more, healthier growth which gradually declines until the next repot. Most people are so convinced that root pruning is bad they refuse to see the evidence right in front of their eyes.
Slip potting, when done correctly, is just one possible tool in our bonsai arsenal. Light disturbance of a tight root ball so there is no barrier between old optimizes slip potting and eliminates many of the problems that can occur. The few roots that are damaged are quickly replaced and the tree almost always has reserves to cope with the temporary loss.


Pots that are way too big can cause problems but there's a difference between 'too big' and 'deep'. Deeper pots actually drain far better than shallow pots. We see in general nursery practice that growers can get away with growing plants in all sorts of potting soil that would horrify a bonsai grower. They are able to do that because of the deeper pots. The shallower the pot the more critical drainage becomes. There is so much rubbish about now telling us that shallow trays are vital and deeper pots are bad. Not true, even from a bonsai perspective. Shallow training pots require very good cultural practices. Deeper pots will usually give better growth and development with less effort.

I'd be confident the trees posted will do fine. I am not familiar enough with your cold winters to know the full ramifications of that but roots do regrow and develop very quickly through the growing season - far more than those who are convinced that root reduction is traumatic can appreciate.
I would follow this slip pot with a full and decisive root prune in spring to check and balance the main lateral roots to set nebari development on the right track.

All super interesting, and the comment about shallow vs. deep pots was really informative. So much knowledge in these forums It's quite amazing.

 

[coh]

Just to add to the debate because, why not...I've "slip-potted" numerous trees over the years with no issues. Generally I try to match up the soil in the existing root ball to the new soil, though I will usually amend it slightly. For example, if I have a nursery tree that is growing in a standard nursery mix (usually heavy in peat and bark), I'll use a soil like that but possibly with some additional components to enhance drainage somewhat. So I'll add some perlite or pumice or lava. If The tree is already in a bonsai soil, I'll just slip it into a container using a similar bonsai soil.

If I have a tree in nursery mix I will definitely NOT slip pot it into straight bonsai soil (or vice versa). I think that is where people get into trouble.

Can also get into trouble if you keep slip-potting year after year. I've done that too, not anymore though. You can wind up with a real mess of a root system that way.

 

[Bonsai Noodles]

Just to add to the debate because, why not...I've "slip-potted" numerous trees over the years with no issues. Generally I try to match up the soil in the existing root ball to the new soil, though I will usually amend it slightly. For example, if I have a nursery tree that is growing in a standard nursery mix (usually heavy in peat and bark), I'll use a soil like that but possibly with some additional components to enhance drainage somewhat. So I'll add some perlite or pumice or lava. If The tree is already in a bonsai soil, I'll just slip it into a container using a similar bonsai soil.

If I have a tree in nursery mix I will definitely NOT slip pot it into straight bonsai soil (or vice versa). I think that is where people get into trouble.

Can also get into trouble if you keep slip-potting year after year. I've done that too, not anymore though. You can wind up with a real mess of a root system that way.

Hmm, good points, and thanks for sharing your experience. In my case, I'm pretty sure Bill V used bonsai soil when he shipped it to me (looks very Boon mix to me). I believe the Arakawa is older, so the soil naturally looks a bit older/decomposed. I took pictures of them just in case — turns out they'll be useful now!

 

[coh]

Hmm, good points, and thanks for sharing your experience. In my case, I'm pretty sure Bill V used bonsai soil when he shipped it to me (looks very Boon mix to me). I believe the Arakawa is older, so the soil naturally looks a bit older/decomposed. I took pictures of them just in case — turns out they'll be useful now!

You should be good. I may have missed it in the thread, but when did you do the potting? Was this recent (like within the past week or two) or earlier in the spring/summer?

I have a very small koto hime (much smaller than these) that I need to slip pot, been thinking about it all summer but never got around to it. Hoping to get it done in the next few days.

 

[Bonsai Noodles]

You should be good. I may have missed it in the thread, but when did you do the potting? Was this recent (like within the past week or two) or earlier in the spring/summer?

I have a very small koto hime (much smaller than these) that I need to slip pot, been thinking about it all summer but never got around to it. Hoping to get it done in the next few days.

Just today actually... Wish I had the vigilance to have done this earlier.

Good luck on yours!

 

[Leo in N E Illinois]

@Shibui - we will just have to disagree. I probably come off fairly dogmatic in my opposition to "slip potting". Though, if you notice, you hardly ever hear of the "masters" talking about slip potting anything. I will admit to occasionally slip potting newly arrived material, young trees and such. But it is very rare, and with extreme caution if I slip pot a mature bonsai tree. It is something that should not be done casually.

I hear "newbies" use the term too often, in situations that could have been avoided. Like some other activities, should be done infrequently, only if necessary.

 

[Shibui]

@Shibui - we will just have to disagree. I probably come off fairly dogmatic in my opposition to "slip potting". Though, if you notice, you hardly ever hear of the "masters" talking about slip potting anything. I will admit to occasionally slip potting newly arrived material, young trees and such. But it is very rare, and with extreme caution if I slip pot a mature bonsai tree. It is something that should not be done casually.

I hear "newbies" use the term too often, in situations that could have been avoided. Like some other activities, should be done infrequently, only if necessary.

I can agree with most of this. I also agree that slip potting is often done badly and often done for no good reason. I note that you admit to slip potting new material and young stock which is exactly what most newbies have access to and what the OP has posted here.
It is likely that the reasons for "masters" not mentioning slip potting is not that they don't or haven't, rather that they spend the majority of their time talking about advanced material and more advanced techniques. It is also likely they would not purchase or grow material that needs the aid of slip potting.
Rather than a blanket ban on a technique as leading to certain death we should be educating people as to appropriate use and appropriate technique and I believe that both were observed in the case of this thread.