Need repotting advice on Japanese maples

[BalconyBonsai]

Hi, I'm new to bonsai and got my first tree this spring. Just last week I received 3 new trees from an online vendor, a japanese maple(no specific variety), a deshojo japanese maple and a trident maple. All of them seem healthy with nice foliage and new leaves forming but the soil they are planted in seems horrible. When pressing it it is really hard and it is not possible to press a finger in to it. When watering, it pools on the surface, eventually draining out at the bottom. On the deshojo it seems there is also a lot of roots on the surface of the soil, to me indicating that it's pot bound? On the trident maple there was also quite a lot of liverworts on the soil.

My question now is whether I need to do an emergency repot of these before fall or if I should wait until spring? I know you are not supposed to repot until the sprung but I am worried the condition of the soil is too bad. I was planning to repot the deshojo(and maybe also the common japanese maple) in the spring anyway into a larger training pot since I would like the trunk to grow a bit larger. I dont know if that will change things since that might mean I won't need to do as much root pruning and maybe that is more forgiving for the trees?

For context, I live in Stockholm Sweden where we will have cold weather in a couple of months. My plan is to build an overwintering shelter on my balcony and isolating the pots with styrofoam and bubble plastic wrap and some sort of greenhouse plastic where these trees will be kept.

Any tips and suggestions will be greatly appreciated!

 

[Deep Sea Diver]

Ok, I’ll step into this one.

It looks like you need to repot these maples. The soil is not draining is the key here. Poor water adsorption even during the Stockholm summer is not going to be good for the health of your trees.

So here’s some thoughts on what I’ve done with 6 of my maples in full leaf 4 weeks ago That were in distress.
Changing the media is likely enough insults for now.

Soak the media and depot. Save a some of the old soil. Rinse the roots with cool water. Mix the part of old media in with the new media. Add to the roots. Water in until the water runs clear. Thump the pot down on the lawn a just little to settle the media, then water in again. Place the trees in heavily filtered sunlight, or mostly shade for 2-3 weeks, then ease into more sun so each can continue building strength until they go into dormancy. Next spring prune those roots and work on the nebari’s

One day last year Bill Valvanis told our club when asked, “When do you repot your Maples?” Bill said, “ Whenever I have time. I just have to ensure they get proper care afterwards.”

Just my thoughts.

Cheers
DSD sends

PS: Your wintering over plan sounds good, as long as the trees go into dormancy (below 42 F) are out of the direct wind, have ventilation and adequate water if not frozen solid.

 

[BobbyLane]

trees look healthy regardless of what you think about the soil. if you repot them now rather than spring, they wont look healthy anymore.

 

[StarGazer]

If you are careful you should be fine repotting now. Here in San Francisco Bay, I tend to repot my Japanese Maples in early spring to allow a full growing season for recovery. Being in Sweden the days are also becoming shorter, so keep in mind that in addition to cold temperatures the trees wont have much time to grow new roots this season, so be as gentle as possible with the roots you have now when you remove the old soil during repotting and root pruning. It seems as if you have made a good plan to protect your trees for the winter, just make sure you protect the roots from freezing.

 

[AJL]

Heres another opinion from the other side of the Atlantic!
Obviously they would benefit from repotting, however they look healthy enough for now so I would leave them till spring then repot . They have grown and survived in the nursery in that soil for a while so delaying a few months till spring should not be a problem.
Bare rooting and repotting now in August in your climate will definately not be beneficial!!
You could try spiking /breaking up the surface crust with a chopstick or screw driver to improve soil aeration and water penetration
If watering is still an issue due to the compacted soil you could plunge them into a trough of water for a good soak periodically.

 

[BalconyBonsai]

Wow, thanks a lot for the quick and thorough responses!

I think I might hold off on repotting them then if you think their current condition does not seem bad enough. Does me planning on repotting atleast one and perhaps two of them in larger training pots change anything? From what I understand that would mean I wouldn't need to disturb the roots too much since they will have more room.

 

[Davidlpf]

Hi.

Every substrate has a specific watering need, so you can adapt your watering habits to the substrate, o the substrate to your watering habits. Both options have risk so YOU must choose the less dangerous for YOU.

If I were you, I'll change that substrates for another more permeable, easiest to watering and better for root grow ASAP. Be aware that "normal" akadama don't work well if it's frequently frozen, so, in Sweden may be better options. Take a look to Walter's blog click,click, his talk about substrates is IMHO, very interesting.

By the way he has made some late summer/early fall repotting, you can read some advices in his blog too click,click

The best time to repot a bonsai is when it is needed

And remmember

Greetings from Spain.

 

[Squirrel7t7]

Heres another opinion from the other side of the Atlantic!
Obviously they would benefit from repotting, however they look healthy enough for now so I would leave them till spring then repot . They have grown and survived in the nursery in that soil for a while so delaying a few months till spring should not be a problem.
Bare rooting and repotting now in August in your climate will definately not be beneficial!!
You could try spiking /breaking up the surface crust with a chopstick or screw driver to improve soil aeration and water penetration
If watering is still an issue due to the compacted soil you could plunge them into a trough of water for a good soak periodically.

Best advise

 

[Deep Sea Diver]

. Does me planning on repotting atleast one and perhaps two of them in larger training pots change anything? From what I understand that would mean I wouldn't need to disturb the roots too much since they will have more room.

Sounds like you are talking about’ slip’ potting. It’s safer with care. You just don’t want too much of a mismatch between media or you can have the undesirable effect of water concentrating in one media or the other. If you match media, you should be fine.

Another idea you might try first is to immerse one of the pots in water for a few hours, take it out and see if the media regains permeability. If that works, try the others and Bobs your Uncle.

Looking at your climatology data, you’ve only until October until the trees will go into dormancy. So at least cover up those surface roots straightaway.

Be sure to follow up over time on this thread with photos etc. so we can see what you did and how it all worked out. It will be interesting as well as helpful.

Best
DSD sends

 

[sorce]

I would Repot today. The moon is good, 2 months till frost is enough, and spring repotting here kills more trees than the zero summer repotting has killed.

Sorce

 

[sorce]

Oops, forgot to mention, Welcome to Crazy!

Sorce

 

[BalconyBonsai]

Hi.

Every substrate has a specific watering need, so you can adapt your watering habits to the substrate, o the substrate to your watering habits. Both options have risk so YOU must choose the less dangerous for YOU.

If I were you, I'll change that substrates for another more permeable, easiest to watering and better for root grow ASAP. Be aware that "normal" akadama don't work well if it's frequently frozen, so, in Sweden may be better options. Take a look to Walter's blog click,click, his talk about substrates is IMHO, very interesting.

By the way he has made some late summer/early fall repotting, you can read some advices in his blog too click,click

The best time to repot a bonsai is when it is needed

And remmember

Greetings from Spain.

Haha, thanks! I will read the blog posts you mentioned.

 

[BalconyBonsai]

Sounds like you are talking about’ slip’ potting. It’s safer with care. You just don’t want too much of a mismatch between media or you can have the undesirable effect of water concentrating in one media or the other. If you match media, you should be fine.

Another idea you might try first is to immerse one of the pots in water for a few hours, take it out and see if the media regains permeability. If that works, try the others and Bobs your Uncle.

Looking at your climatology data, you’ve only until October until the trees will go into dormancy. So at least cover up those surface roots straightaway.

Be sure to follow up over time on this thread with photos etc. so we can see what you did and how it all worked out. It will be interesting as well as helpful.

Best
DSD sends

Yes, I think slip potting is what I mean. So when slip potting a lot of the old soil/media is transfered over to the new pot? I thought I still needed to "clean" the roots to some extent but maybe that is enough to upset the tree?

Can I ask what source you used to know when the trees go in to dormancy here? What should I use to cover up the surface roots? Something like pumice?

I will try to remember to keep this thread updated as I go.

Thanks!

 

[BalconyBonsai]

I would Repot today. The moon is good, 2 months till frost is enough, and spring repotting here kills more trees than the zero summer repotting has killed.

Sorce

Hi and thanks! The problem is that since this issue came up unexpected I don't really have anything to use as substrate that I think would be usable for bonsai. I would need to order online so I would lose I think another week until I could repot. Would it still be enough time do you think before winter/dormancy?

Also, is your answer regarding repotting the trees in new bigger training pots or a normal repot with a lot of root pruning? I should also add that I have not really done a repot of a bonsai yet, I have repotted "normal" container trees but it doesn't seem the same, so it is probable that I will make some mistakes.

 

[sorce]

Would it still be enough time do you think before winter/dormancy?

It wouldn't be the time till frost that makes it a no but the time after the full moon. A week after is kinda late. And the next Full moon would be too late.

So you're better off waiting. Take the whole winter to source good, easy, cheap substrate.

Definitely cover the roots, but not before jamming a toothpick in the soil a bunch to aerate it, and so water can penetrate.

Sorce

 

[Davidlpf]

Yes, I think slip potting is what I mean.

Slip potting not solve the problem, only hide it!


Bad soil, in the center of the root ball, may suffocate the young, and more interesting roots in that area. And the watering retention don't be better.
If the tree is lucky enough may develop new root in the new substrate in the outer part, and perhaps will survive, but you will lose the inner roots, that is a bad thing.
I wouldn't trust much in that option, if you want a dense root ball in the future.

But the decision is only yours.

It wouldn't be the time till frost that makes it a no but the time after the full moon. A week after is kinda late. And the next Full moon would be too late.

I hope you're kidding. Base the repotting schedule in the moon phases nowadays, is how to say that the earth is plain. You may believe it, but simply is not true.

Cheers.

 

[sorce]

plain

Plane? Like flat?

I believe our technologies, like chemical bullshit, and more chemical bullshit, has allowed our new crops, also chemical BS lol! The ability to grow ok without following moon patterns.

But in our move back to Loving Earth, and not using all that chemical BS and GMO engineered plants, the moon is EVERYTHING! Or at least 2%.

Sorce

 

[Davidlpf]

Plane? Like flat?

I believe our technologies, like chemical bullshit, and more chemical bullshit, has allowed our new crops, also chemical BS lol! The ability to grow ok without following moon patterns.

But in our move back to Loving Earth, and not using all that chemical BS and GMO engineered plants, the moon is EVERYTHING! Or at least 2%.

Sorce

Of course that if you believe that repotting complete naked under the full moon light may be better for yours plant, you're in your right to do it. But there't ANY real evidence that the moon has positive or negatives effects.

Click,click

 

[sorce]

Of course that if you believe that repotting complete naked under the full moon light may be better for yours plant, you're in your right to do it. But there't ANY real evidence that the moon has positive or negatives effects.

Click,click

It merely says they didn't find any lunar influence, not it doesn't exist.

And the talk of "primitive", when speaking of our ancestors is foolish. So that discredits the article for me. Our ancestors were smarter than us.

Sorce

 

[sorce]

And here I been thinking lpf stands for Lunar Phase Follower!

Sorce