Air pruning in colanders?

[markyscott]

Forgot to include the link to the article he references:
ALWAYS back check a reference. In this case I think
his correlation between the sourced material and bonsai
is tenuous at best. Read the abstract of what the article
actually addresses HERE.

Thanks Armetisius - I also found the full reference.

http://hort.ifas.ufl.edu/woody/documents/articles/EFG0901.pdf

The objective of the study was to evaluate the described shaving technique as a means of avoiding encircling roots on nursery grown plants. The primary issue that they were addressing was stability of nursery trees in the landscape - apparently trees with roots issuing radially from the trunk are more stable than trees with encircling roots. Control was provided by trees up-potted without anything having been done to the rootball - they reported that growth was not affected by shaving vs control. The results were measured by a qualitative evaluation of the rootball and the degree to which encircling roots were eliminated by the shaving, not by growth rates. There was no quantitative comparison of growth rates following the shaving technique to any other root pruning technique used by nurserymen (let alone bonsai growers). However, they did offer a very interesting but qualified (and qualitative) comparison to other studies which did look at growth rates:

"This demonstrates as others have shown (15) that container grown shade trees receiving regular irrigation can recover from severe root pruning without slowing their shoot growth."

With reference to the original question posed by the opening post, there was a reference in the paper to "air pruning", which may be equivalent to planting in a colander. Their characterization of air pruning was the following:

"Seedlings in air-pruning 5 cm (2 in) diameter containers had less packed roots, less spiraling roots, and fewer L-shaped roots (25). The authors noted that seedling grown trees in air-pruning containers produced less root defects than those grown in solid-walled containers, but they had slower root and canopy growth in the nursery due to the lateral air- pruning (25)."

I found those two conclusions fascinating as it seems to suggest that severe root pruning of container plants does not affect growth rates but air pruning does. I'll see if I can track down the other reference.

Scott

 

[Adair M]

I might also add that an open soil like bonsai soil would dry out faster around the edges of a colander than if the soil were a type more of the heavy peat based soils used by most nurserymen. Those soils tend to retain more water than coarse bonsai mix, thus rendering the use of a colander less effective.

 

[markyscott]

Thanks Armetisius - I also found the full reference.

http://hort.ifas.ufl.edu/woody/documents/articles/EFG0901.pdf

The objective of the study was to evaluate the described shaving technique as a means of avoiding encircling roots on nursery grown plants. The primary issue that they were addressing was stability of nursery trees in the landscape - apparently trees with roots issuing radially from the trunk are more stable than trees with encircling roots. Control was provided by trees up-potted without anything having been done to the rootball - they reported that growth was not affected by shaving vs control. The results were measured by a qualitative evaluation of the rootball and the degree to which encircling roots were eliminated by the shaving, not by growth rates. There was no quantitative comparison of growth rates following the shaving technique to any other root pruning technique used by nurserymen (let alone bonsai growers). However, they did offer a very interesting but qualified (and qualitative) comparison to other root pruning techniques used by nurserymen:

"This demonstrates as others have shown (15) that container grown shade trees receiving regular irrigation can recover from severe root pruning without slowing their shoot growth."

With reference to the original question posed by the opening post, there was a reference in the paper to "air pruning", which may be equivalent to planting in a colander. Their characterization of air pruning was the following:

"Seedlings in air-pruning 5 cm (2 in) diameter containers had less packed roots, less spiraling roots, and fewer L-shaped roots (25). The authors noted that seedling grown trees in air-pruning containers produced less root defects than those grown in solid-walled containers, but they had slower root and canopy growth in the nursery due to the lateral air- pruning (25)."

I found those two conclusions fascinating as it seems to suggest that severe root pruning of container plants does not affect growth rates but air pruning does. I'll see if I can track down the other reference.

Scott

I checked the air pruning reference. The quoted study was for Pinus radiata grown in air pruning containers - not close at all to the species in the "shaving" study. I could only access the abstract for the Pinus radiata study:

http://link.springer.com/article/10.1007/s11056-004-7364-6

Perhaps someone else can find the complete reference. In their abstract, the authors in the air pruning study report slower growth rates but fewer root defects. I don't know how comparable that is to the tropicals and temperate deciduous species discussed in the root shaving study.

Scott

 

[0soyoung]

http://link.springer.com/article/10.1007/s11056-004-7364-6

Perhaps someone else can find the complete reference.

http://ria.asturias.es/RIA/bitstream/123456789/2165/1/Fiield performance.pdf
This is about seedlings grown in 'tubes' about 2"x 2"x 6" in size (small! --> seedlings grown as plugs).

From the paper:

Due to the slots in the container sidewalls, PF200 stock’s growing media dryed up faster during production compared to stock produced in the three types of hardwall containers. Because of the impossibility of applying extra water to a small number of PF200 seedlings growing operationally among a large amount of hardwall stock, the PF200 seedlings presented worse growth and biomass.

Seedlings grown in the grille-shaped containers produced the least root biomass and least root surface, due to lateral root air-pruning rather than to container volume. However, this container type is the most advantageous one with respect to root system quality.

 

[eferguson1974]

Which we know are purple thongs. Its a bnut thing....

 

[eferguson1974]

http://ria.asturias.es/RIA/bitstream/123456789/2165/1/Fiield performance.pdf
This is about seedlings grown in 'tubes' about 2"x 2"x 6" in size (small! --> seedlings grown as plugs).

From the paper:

The 3' pine I was given was in a tallboy beercan size bag, and starting to escape the holes. I slip potted it into a big square planter, I need a deeper colander or coffee basket.
Anywho I took a pic or two of my bougie escaping roots. Yoday I noticed new growth up where I thought it was dead, and lots more below. So its looking up for the strangler freak's bougie!

 

[0soyoung]

The 3' pine I was given was in a tallboy beercan size bag, and starting to escape the holes. I slip potted it into a big square planter, I need a deeper colander or coffee basket.

You can

1. plant it on a slant to maybe get it to fit
2. bend the tap root to maybe fit
3. trim the tap root to maybe fit (certainly can be done progressively)

Anywho I took a pic or two of my bougie escaping roots. Yoday I noticed new growth up where I thought it was dead, and lots more below. So its looking up for the strangler freak's bougie!

Congrats!

 

[Anthony]

For What It is Worth,

For US - colanders are best for ground growing, as you can lift after 1/2 /3 years and have enough root in the
colander for no real stress to the plant.

If you use the AIR POT the air pruning bit works.
The plant comes out with a much denser root mass and can support a heavier canopy, right from the start of
in the Bonsai pot.

** Ficus is immune to air root pruning as they grow roots in the air naturally.**

The AIR POT however can use 100% compost and so -- may -- be able to be used for a bypass ground growing technique.

The colander did not air prune anything for us, in our test subjects.
It is a convenient shape for other uses.

We cut off 1" or so [ depends on the size of the Bonsai's root mass ] when we repot from the sides and underneath.
Then comb back a 1/2 " or less of the mass.
Causes no disturbance to Health or having to tie the tree into the pot, just the weight the root mass is sufficient to keep
the tree in the pot.
Additionally, the breeze rocking is supposed to help the tree, stimulates the growth of anchoring roots.

The soil mix we use - seems - to discourage root thickening. Checked all of the 30 year old trees [ from seed or cutting ]
So we never need to - BARE ROOT - just what is described above.

Sorry, we are not a Science Research team, just offering our experiences.

The idea was to simplify Bonsai Techniques.
Good Day
Anthony

 

[Waltron]

Hmmm...

I wonder if the use of colanders is addressed in that Morton book with the Walter Pall pictures.

Also, I wonder if he addresses the Ebihara technique for deciduous?

@rockm. Any comment?

I asked the same question..

 

[0soyoung]

The soil mix we use - seems - to discourage root thickening.

Clay-ridden/sticky dense soil will force roots to thicken over the course of a few years. Loose/airy media will instead support lots of fine roots. The effect arises from the resistance the root tips experience while pushing ahead (growing) - harder to push --> thicker root.

 

[Random User]

"Additionally, the breeze rocking is supposed to help the tree, stimulates the growth of anchoring roots."

Buttress roots are developed in nature as the tree rocks. Restricting the buttressing and thickening of roots (by restricting the rocking) potentially reduces the quality of the nebari. Obviously this is not an issue if you are working on a thick, developed stump, but if you are growing a 4-7' whiplike tree to thicken the base before doing a chop, it might effect the quality of the base if you restrict the tree from it's natural motion.

(Now the Walter Pall praise, because I like his straight talk...) I'm ad-libbing from recall... this is not verbatim but basically he says... the nebari is the first place that you look and the most important feature of a tree and how it will ultimately be designed... a poor nebari now, no matter how well the top developed, will always be a poor nebari 30 years from now... I don't think anyone could reasonably argue this fact.

But, what works in one part of the world is different than others, along with the material you are working on, your personal preferences, commitment to your own philosophies, etc.

Happy bonsai'n!

 

[Waltron]

For What It is Worth,
For US - colanders are best for ground growing, as you can lift after 1/2 /3 years and have enough root in the
colander for no real stress to the plant.
Anthony

my one question about this, and it comes from a photo I saw, is on a newly collected conifer, planted into a colander, then the colander planted into the ground, or other substrate surrounding colander, the pines roots will eventually grow outside the colander into the substrate through the colander holes, but then at first repot, you have all these fragile pine roots stuck through the colander, I see that as a big problem.

look at this link ,scroll to the bottom, click on southwestern pine #4 at the very bottom right, the first two photos will describe what my concern is perfectly. those roots will be hard to salvage I think.

https://e224121430280313e297bcf31dd.../host/0B_a4Lp9gol_taHAxeXN1NV94TzA/pines.html

 

[Random User]

"FWIW, I hardly agree with everything in it. I think, however, that the most important thing about it is it might get people to actually think about what they're doing, instead of just doing it because someone said it's the way to do it, because of some time-worn superstition or overhyped product literature."

I agree; never let the access to information, prevent you from thinking for yourself. (But sometimes, even misinformation can stimulate a valuable change in the way we approach problems.)

 

[Anthony]

@Waltron,

for what is worth, some trees can trunk thicken in a pot e.g. Ficus in a 1" deep pot.[ a Texas Ebony, a Chinese Elm.........but deeper pots ]
[
The colander within a colander, within a colander, within yet another colander, would give to such a
tree an effect similar to open gound - I offer as the reason.

As you cut back there will be fine roots as well as thicker roots. Probably keeps the tree stable.

If you look at the Japanese black pines in clay pots in Bonsai Today [ is it issue 12 or 20 ?], the 3 to 5 inch trunks are from
growing in 12 to 16 inch x 6 inch deep pots over 5 plus years.
Which - may - indicate that the J.B.pine can trunk thicken in a pot.

So if you are limited for land and ground growing, a colander in a colander in colander ................
And you keep going flatter and broader as the "pot" goes.
Good Day
Anthony

 

[Waltron]

hmm I guess my question is this: is a colander really a good idea for a newly collected pine? I've seen dissenting opinions, "the colander idea is full of holes" saying the anderson flats are better, because the weaker pine roots dont get air pruned, with the thought that air pruning fragile newly collected pine roots could be counter productive to what you are trying to accomplish, and could cause negative effects on the health of a newly collected pine, which is first order of business, shaping roots being less important. Now that instance would be in a colander, not in the ground. the photos in the link i posted above, sort of reinforce my thoughts, but would be related to a newly collected pine, in a colander, in the ground, Curious to know if anyone understands what im getting at, and if they do, what is their opinion on the matter, and also if anyone wants to go in on an order of anderson flats lol, those things are pricey with shipping.

 

[Starfox]

What I have found interesting is I'm starting to see air pots being recommended for keeping bigger trees in pots, in not so much an imperial bonsai way but more a court yard gardening type of way. Instead of reducing the size you just keep up-sizing the air pot. Not sure if it has always been recommended but the idea is gaining traction it would seem or it's being commercialised. It makes sense in pot culture so I plan on trying it on some non bonsai trees.

 

[Random User]

@Waltron

http://www.bonsainut.com/members/jeanluc83.14224/

Not sure if the link will work... if it does, what difference would this box (if it has screen sides) be to the Anderson flats?... basically, could you not just build your own? (Especially if you are just experimenting.)

 

[Waltron]

not sure what that link is, but yea, I can build my own pretty easily, i just want an anderson, they look nice. welding plastic is somewhat difficult. I can make one very easy out of metal

 

[Random User]

F A N C Y man!... that could be really advantageous (but for limited use).... for example, if you saw your prospective tree to go into a particulal size oval pot... you could just make removable sides that got progressively larger season by season, until you got what you required. When you got to your optimal size, you wouldn't have to disturb the vast majority of the roots at all, just plunk it straight into the pot. (Don't worry, I realize this is a far-fetched! ... lol.)

 

[eferguson1974]

I just want to explain, I read about air pruning but use colanders for other reasons. One, its wet here for 6-8 months. So soil doesnt dry well. The combo of gravel colander prevents root rot. And I thought it would help prep for a small pot. So when I saw the inch long white roots around the lower bottom, it surprised me. I thought the bougie was a gonner. I already cut off the thick roots.
Another thing Ive found is that the holes in the colander make it easy to tie in with tomato string when planting. A week or two later and you can cut off the string, when the tree is stable.
Its worked for me.
Right now Im going to just let it get healthy and see where it buds..