Ryan Neil's Latest Repotting Video

[BobbyLane]

Im a simple man....as long as the media is free draining or water runs through the drainage holes within a matter of seconds and the root ball is fully soaked im good and the tree is usually good. this happens with most mixes, combinations or soils ive come across, nursery soil, trees in part field soil surrounded by bonsai mix etc. Unless there is a serious problem with drainage. in which case further measures are taken. even dense soil tends to loosen up after a few aggressive waterings, or dunks and water usually begins to run through quicker, again unless there is a serious drainage problem.

 

[Wills612]

Lodgepole? Nice movement

Yea I collected a few nice ones last summer.

 

[Gabler]

The way I've heard it explained is the perched water table is a function of gravity and the bottom of the pot. Gravity works less and less on the water as it nears the pot bottom. Since there is no impenetrable boundary between the upper field soil and the lower bonsai soil., gravity and capillary action will cause the water to gradually make it's way to the bottom, albeit a bit slower through the denser, field soil.

I don’t know about you, but I don’t have an impenetrable barrier at the bottom of the pot. Just a mesh over the drainage holes. If you put field soil over pumice, it’s no different than putting that same field soil over drainage hole mesh. It’ll support the same amount of water from that point up.

The water table isn’t a function of depth alone. It’s a function of how much water a particular soil can support via capillary action against the force of gravity pulling that water down and out of the pot. The smaller the particles’ size, the smaller the distance the tension of the water has to bridge between particles, and the more mass it can support above it.

 

[Joe Dupre']

I should have said "nearly impenetrable". That would be more accurate. I haven't studied the science, but it seems counterintuitive that gravity and capillary action together would not draw excess moisture out of the upper field soil into the lower absorbent bonsai soil. I can see that the rate would be considerably slower, but I can't see it stopping altogether. I might have to do an experiment.

 

[Gabler]

I should have said "nearly impenetrable". That would be more accurate. I haven't studied the science, but it seems counterintuitive that gravity and capillary action together would not draw excess moisture out of the upper field soil into the lower absorbent bonsai soil. I can see that the rate would be considerably slower, but I can't see it stopping altogether. I might have to do an experiment.

I think it’s a misunderstanding of how capillary action works. Capillary action draws water from open spaces into narrow spaces. It’s why a paper towel soaks water up from the floor. It doesn’t work with gravity to aid drainage. It works against gravity to hold water aloft. I mean, it technically could work with gravity. I’ve seen drip watering systems based on that principle. But that’s not what I’m talking about. With water in the soil, it’s capillary action pulling up against gravity pulling down.

 

[Joe Dupre']

What I thought I was referring to was capillary action but I was mistaken. What I was referring to was moisture transfer. Wet soil will transfer moisture to drier surrounding soil. As the the roots in that drier soil use moisture, it will be replenished by more moisture drawn from the wetter soil. All field soil in a bonsai pot..........not good. Minimal field soil mixed with a majority of bonsai soil.............don't see a problem.

 

[Gabler]

What I thought I was referring to was capillary action but I was mistaken. What I was referring to was moisture transfer. Wet soil will transfer moisture to drier surrounding soil. As the the roots in that drier soil use moisture, it will be replenished by more moisture drawn from the wetter soil. All field soil in a bonsai pot..........not good. Minimal field soil mixed with a majority of bonsai soil.............don't see a problem.

Ah. Now I see what you’re saying. I’m glad we clarified our terms, because I completely missed what you were going for.

In spite of capillary action holding excess moisture in field soil, with enough surrounding free-draining soil, the moisture level will even out to an extent. In that case, I would assume that a larger, deeper pot would benefit newly-collected material with field soil in the root ball, even if it is able to physically fit into a smaller pot.

I would also guess that shohin-sized grains would further improve drainage, facilitating transfer of moisture from the field soil to the bonsai substrate compared to larger grains of the same substrate material.

I would also guess that a product like NAPA 8822 would do a good job wicking excess moisture out of the rootball. Each individual grain is dense and highly absorbent, but the moisture evaporates quickly because of the large surface area of the grains collectively. It would give you both the advantage of capillary action and the tendency of water to spread to areas that are relatively dry.

 

[Japonicus]

it is based on a term and approach used by Kimura, in Japanese it means heart.

I'm glad you posted this. I've referred to the crown/shin as the heart of the tree before
with no clue that it was portrayed this way by anybody, much less such an artist.
It is just seat of the pants common sense to me.

I also liked the post (forget who it was, but) saying the shin with old soil gives purchase for securing.
Being self taught and only one workshop under my belt, (where I did no work, rather listened and asked questions)
I have difficulty properly securing trees with a clean shin. How I approach this, is removing more of the field soil
with each subsequent repot, and working a little bit on the shin while filling with new soil.
Yes that displaces field soil into the new soil, but it is a minimal invasion I am doing, and will attend to it next time.
I have trees over 15 and 20 years (one 24 years) still, with original soil in the shin.

Repotting is my most stressful part of bonsai. It brings out the most paranoia I have with the hobby.
I always fret over my trees after repot, and I've been doing it probably 25 years now.
I would not have a good day, if I had nothing to worry about I guess.

 

[MrFancyPlants]

I think my literati Tsuga might be a good candidate for a top down approach this Spring. I’m trying to figure out a way to attempt, but put it back in the same nursery pot it has been in. The silt it is in currently is so fine, I’m thinking I could cut a large hole in the side of the pot and rinse my way down for a relatively gently bare rooting. And then mesh over the hole when I am done. Or cut down the pot and mesh it all the way around the friable aggregate?

The wheels are turning; It is an emergency repot as I’m 50/50 it will make it through Spring if I do nothing. The tree is pretty weak.

It’s funny, parts of the tree are much stronger this Spring, and parts have given up. The parts that are strong are much stronger than last year’s growth, so I am going to wait until next year to do the top-down. Let it gather some energy first.

 

[Bonsai Forest]

I'm curious, but not curious enough to sign up just to ask a single question about a technique's provenance.

Just call him or his staff and ask them directly lol