FinnLakk
Yamadori
To put it in pizza terms, one 18 inch pizza contains more pizza than two 12 inch pizzas
Why Not Have Many Tiny Drainage Holes?
- Thread starter DrTolhur
- Start date
NaoTK
Chumono
Mr.Dr.K
Sapling
Not a bad idea. I've always moved my trees under cover during heavy rain in spring and fall to mitigate sogging. I only have two trees, though, that stay out. Can I ask what your potting medium is? I'm wondering what the magic formula is that drains well enough with excessive spring-rain and yet holds enough moisture on a full day of hot, dry, miserable, summer sun.
rockm
Spuds Moyogi
Inadequate drainage in pots has nothing to do with tradition. It has to do with not really understanding how bonsai pots are supposed to function. FWIW, I've got a 19" nakawatari Chinese oval pot-which was made between 1800 and 1911 (the range of "second crossing" pots imported from China to Japan). Anyway, the pot bottom is markedly convex inside the pot, with only two quarter-sized drain holes at the "ends" of the oval. The holes are placed so they drain not only the bottom, but a bit up the sides of the concave portion. That leaves not much area for the water to pool as it drains off the slight hump in the bottom The pot drains VERY well with only those two holes. Location, location, location...
Deep Sea Diver
Masterpiece
There is no magic formula needed, just a good media. Personally I use standard Boon Mixes for all trees but azalea, which get 90/10 kanuma/pumice….
…But others out here use different medias or combinations of media with no issues of drying out by chocking their pots up.
I’ve been known this chick up entire tables of bonsai during extended rainstorms just to save time!
Cheers
DSD sends
Deep Sea Diver
Masterpiece
That’s the better design strategy for sure.
It’s kind of interesting too, as awhile back we were repotting a biggish tree, that was in an antique pot, that wasn’t doing so well. When we got the tree out it was discovered that the center root area was soggy and otherwise on bad shape.
When I went to wash the pot it had two holes one on each end, I did a flow test just curious. Turns out the pot bottom was concave… leaving the drain holes high and dry with a permanent puddle between the two. Since then I always flow test all pots when repotting, no matter where I am.
I used to sorta think this issue had to do with ancient potters not understanding drainage… but that couldn’t possibly right as your examples shows. I just think there are novices in every age and one needs to double check all pots out, ancient or modern.
Best
DSD sends
HorseloverFat
Squarepants with Conkers
Joe Dupre'
Omono
Did anyone think about the other important ingredient besides water? Air. In such a small enviornment, air needs to get in and out efficiently. Just a hunch, but I feel air has a much better chance of flowing freely through a couple of large holes than several small ones........hence pond baskets and mesh pot bottoms. In effect, pond baskets and mesh bottoms are really big holes with a lot of mesh covering them.
DrTolhur
Mame
I feel like you could also say, though, that pond baskets are in effect a solid surface with many holes put in it. The bigger difference in why we can't really compare that to bonsai pots is the other distinctions between them, like material and thickness, which seems to be where the main issues people are suggesting come from.
River's Edge
Masterpiece
smaller holes plug up easier, going in the wrong direction.
ShadyStump
Imperial Masterpiece
My understandings from the conversation so far.
Ceramic pots require there to be fewer, big holes to maintain structural integrity under various conditions.
Smaller holes, but of a size functional in ceramic pots, plug up relatively easily. How this works relative to the screen we use over the holes is still up for debate.
Larger holes, via the properties of water and laws of hydrodynamics, allow for faster, smoother, more thorough drainage than small holes.
Larger holes allow for greater atmospheric exchange.
Small holes may be of more practicality when materials other than ceramics are used, assuming the balance of the above qualities is maintained.
Tradition and pot engineering play their parts. Example; small holes in an otherwise well designed pot can be more effective than large holes in an illdesigned pot, but you're more likely to see large holes regardless because bonsai pots just have large holes, damnit.
Anything I missed.
Ceramic pots require there to be fewer, big holes to maintain structural integrity under various conditions.
Smaller holes, but of a size functional in ceramic pots, plug up relatively easily. How this works relative to the screen we use over the holes is still up for debate.
Larger holes, via the properties of water and laws of hydrodynamics, allow for faster, smoother, more thorough drainage than small holes.
Larger holes allow for greater atmospheric exchange.
Small holes may be of more practicality when materials other than ceramics are used, assuming the balance of the above qualities is maintained.
Tradition and pot engineering play their parts. Example; small holes in an otherwise well designed pot can be more effective than large holes in an illdesigned pot, but you're more likely to see large holes regardless because bonsai pots just have large holes, damnit.
Anything I missed.
0soyoung
Imperial Masterpiece
Big holes plugged up with a mesh of small holes is obviously better?
For simplicity lets say the substrate is sieved through a certain sized mesh. It (the sifted substrate that consists of particles of a smaller mesh size) is going to fall through any lager sized container holes.
ShadyStump
Imperial Masterpiece
Thinking on it for a moment, I think the small hole size on the mesh doesn't clog because the grain size of substrate is often significantly larger. The irregular size of the substrate particles prevent them from sealing against the fibers of the mesh. Yet it still allows ample drainage BECAUSE of the large holes in the pot. The mesh, aided by the aforementioned properties of water, drains across its entire surface as water wicks from the outer fibers the ones in the center, but only the area congruent with the hole.
Edit: Re-read, and the relationship between the large holes and the mesh wasn't made clear.
If there was just a large hole, no mesh, then the water would run out at the edges of the hole, the rest of the area being unnecessary. With mesh, however, the water will drain out slower. We've effectively reduced the hole size.
In conjunction, the mesh can only drain over the area of the hole, but effectively reduces size of the hole by say 50% (for the sake of example), therefore a larger hole is needed. Even so, the mesh aids in drainage by wicking the water via capillary action and surface tension across its entire area, draining as effectively as if the hole had been reduced by only 25% (again, just a number for the sake of example).
Edit: Re-read, and the relationship between the large holes and the mesh wasn't made clear.
If there was just a large hole, no mesh, then the water would run out at the edges of the hole, the rest of the area being unnecessary. With mesh, however, the water will drain out slower. We've effectively reduced the hole size.
In conjunction, the mesh can only drain over the area of the hole, but effectively reduces size of the hole by say 50% (for the sake of example), therefore a larger hole is needed. Even so, the mesh aids in drainage by wicking the water via capillary action and surface tension across its entire area, draining as effectively as if the hole had been reduced by only 25% (again, just a number for the sake of example).
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Joe Dupre'
Omono
I'm going with this one.
Deep Sea Diver
Masterpiece
Hmm …why would these statements not be valid in ordinary situations we run into?
…. The type of material doesn’t matter to physics vis a vis water and air flow through orifices, while size of the hole does .… and perhaps thickness to-a minor extent while type of material and thickness does in a heat transfer or retention situation.
Best
DSD sends
Emanon
Mame
To jump the shark... What if you used a ceramic mesh screen to cross the large hole of a bonsai pot instead of the plastic ones? I know that "ceramic fibers" exist but I know nothing about the technology. But say you can use something like this (something similar to fiberglass mesh but made out of ceramic fibers) to mimic the exact dimensions (thickness and gauge) of the plastic screens we all use...
Or what if you incorporated a ceramic mesh into the manufacture of a ceramic pot...so that this ceramic mesh was the entire bottom of the pot and fired it all together (so the pot looked exactly like a plastic Anderson flat but made entirely of ceramic)?
Again, I know nothing about the ceramics, but I did a quick Internet search and found companies that manufacture something called ceramic honeycomb structures (usually used as filters). (The first picture below.) I think a pot bottom that was made up entirely of a ceramic honeycomb structure like the one in the picture that is shaped like a hexagon might be durable and allow for good drainage? We also already mass-produce inexpensive ceramic soldering blocks that you think could easily be incorporated into the design of mass-produced pots (i.e. the entire bottom of a pot being something like the round ceramic soldering block in the third picture below). But we don't do that. And it sounds like the arguments above against tiny holes are the reason why?
[I'm not thinking about bespoke hand-made pots but a company like Anderson but not Anderson...one that specializes in ceramics and maybe already makes ceramic soldering blocks... could easily produce a pot with an entirely holed bottom like an Anderson flat but made of ceramic.]
Or what if you incorporated a ceramic mesh into the manufacture of a ceramic pot...so that this ceramic mesh was the entire bottom of the pot and fired it all together (so the pot looked exactly like a plastic Anderson flat but made entirely of ceramic)?
Again, I know nothing about the ceramics, but I did a quick Internet search and found companies that manufacture something called ceramic honeycomb structures (usually used as filters). (The first picture below.) I think a pot bottom that was made up entirely of a ceramic honeycomb structure like the one in the picture that is shaped like a hexagon might be durable and allow for good drainage? We also already mass-produce inexpensive ceramic soldering blocks that you think could easily be incorporated into the design of mass-produced pots (i.e. the entire bottom of a pot being something like the round ceramic soldering block in the third picture below). But we don't do that. And it sounds like the arguments above against tiny holes are the reason why?
[I'm not thinking about bespoke hand-made pots but a company like Anderson but not Anderson...one that specializes in ceramics and maybe already makes ceramic soldering blocks... could easily produce a pot with an entirely holed bottom like an Anderson flat but made of ceramic.]
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ShadyStump
Imperial Masterpiece
This is the balance I mentioned. The physics of drainage vs the structural integrity of the pot.
Small holes all over result in regions of lower mass that will be more prone to shrinkage and expansion as temperatures change, and thus more subject to breakage.
Slightly smaller holes and one or two more wouldn't be problem here, except as mentioned by some of the potter's that chimed in holes at all can lead to warping as the clay dries and subsequently as it's fired. So make as few holes as possible.
ShadyStump
Imperial Masterpiece
See my last post for arguments there.
I'll add that while the technology may exist to make a pot like you described, there's likely little encouragement to do so. We've obviously already solved the problem at minimal experience, and the cost to make a pot with a ceramic fiber bottom would likely out pace the market's desire for one. They'd have to be mass produced to keep costs low, but still of exceptionally high quality- both structurally and aesthetically- to justify the cost manufacturers can't cut. It just couldn't compete on the market with the existing standard processes.
NaoTK
Chumono
I think its just the thickness of the mesh material and the tendency of dirt to stagnate on the edges of the tube and clog as the tube gets longer. Through capillary action, stagnation, stiction etc.
You could theoretically make a pot floor where the thickness decreases around the built-in mesh. There shouldn't be any weakness from the mesh making the clay thinner. It's not going to crack in freeze or anything like that. It is more difficult to make (I have an idea though around that) Fuck it, I'll make one.
You could theoretically make a pot floor where the thickness decreases around the built-in mesh. There shouldn't be any weakness from the mesh making the clay thinner. It's not going to crack in freeze or anything like that. It is more difficult to make (I have an idea though around that) Fuck it, I'll make one.
andrewiles
Shohin
Can't wait to see what you come up with!
I wonder if anyone has tried the extreme: exclude the entire bottom of the pot except for a lower lip, and use a removable rigid plastic mesh instead. Maybe a screen on top of that. E.g. like this.
I'm sure there are meshes out there that are strong enough to hold the weight of soil and a tree for decent sized pots. This is one case where technology today enables something that was not possible in the recent past. Certainly make for a lightweight pot with great drainage.
I wonder if anyone has tried the extreme: exclude the entire bottom of the pot except for a lower lip, and use a removable rigid plastic mesh instead. Maybe a screen on top of that. E.g. like this.
I'm sure there are meshes out there that are strong enough to hold the weight of soil and a tree for decent sized pots. This is one case where technology today enables something that was not possible in the recent past. Certainly make for a lightweight pot with great drainage.
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