What is the smallest 'sustainable' bonsai size?

[JoeWilson]

I watched an interesting video recently about how to keep mame-sized bonsai alive. The basic idea is to put the tiny pots in a larger base with moss/dirt so they don't try out too quickly, and let the roots extend out of the pots (trimming them occasionally). I'm not sure if some people would consider this cheating or something, but it seems effective.

 

[Attmos]

The issue with rapid desiccation, dehydration, is not unique to the smallest bonsai. Any time the pot size (and this implies root mass) relative to the mass of foliage a tree is supporting becomes unbalanced, desiccation is a serious risk. A meter tall juniper in a very shallow pot, may also dry out just as quickly as a bean size Ficus. If you can only water once a day, you need to use larger pots, and allow larger soil media masses than if you had reliable 3 times a day watering service. Emphasis on reliable. For most of us this is a hobby, so we need to use larger pots relative to the small size of the tree to "buy time" to allow the tree to survive our ability to keep up a watering frequency. Once a day is my personal maximum. I increase the pot size for any tree that seems to dry out too quickly.

Some trees, like azalea and maples are pretty sensitive to a hard drying out. Drying out is fatal. One alternate approach is to work with species that tolerate drying out between watering. Here various desert shrubs and arid region species are advantageous. Most drought adapted species have some adaptations that pose challenges for bonsai, for example, pachycaul species (some trees, some shrubs) have a layer of spongy water storing tissue under their bark. This expands and contracts with moisture levels. This causes bark to exfoliate, an attractive feature in most, but creates issues when trying to shape by wiring. These are "best" as clip and grow. Some pachycaul species worth looking into are Bursera, Boswellia and Commiphora. Bursera is the source of copal resin, Boswellia is the source of frankincense resin and Commiphora is the source of myrrh. I have experience only with Bursera, and I find the fragrance delightful when working with it, repotting or pruning.

If kept cool and dry a Bursera with a one inch diameter base can go 4 months without water. They will drop their leaves during dry spells. If kept warm, above 60 F, (+15 C) and watered regularly they will grow fairly fast and keep their leaves. Bursera are opportunistic, they grow with heat and water, regardless of astronomical season.

Thank you 'Professor', that's a great explanation. Proportion and balance are pretty much what mother nature craves, so it makes sense to work with agreeable species as opposed to water-hungry trees and shrubs.
Western US species sound like ideal trees to work with in this case. Midwestern trees seem to mostly love wet soil. I guess I asked because of the sheer number of "yardadori" Eastern Red Cedars. They seem to tolerate drought pretty well, and they don't grow very quickly.

I thought I might grow a few to a decent size and cut them back to fit a 'mame' size pot. I know ERC isn't popular, and a potential carrier of 'apple rust", but there are just so many of them that I feel almost obligated to give them a try. lol

 

[Leo in N E Illinois]

Thank you 'Professor', that's a great explanation. Proportion and balance are pretty much what mother nature craves, so it makes sense to work with agreeable species as opposed to water-hungry trees and shrubs.
Western US species sound like ideal trees to work with in this case. Midwestern trees seem to mostly love wet soil. I guess I asked because of the sheer number of "yardadori" Eastern Red Cedars. They seem to tolerate drought pretty well, and they don't grow very quickly.

I thought I might grow a few to a decent size and cut them back to fit a 'mame' size pot. I know ERC isn't popular, and a potential carrier of 'apple rust", but there are just so many of them that I feel almost obligated to give them a try. lol

I let myself get distracted with typing about the desert trees. What I really was trying to emphasize was the need to balance pot size and root mass so that you can get away with watering just once a day. Maples, and elms are the epitome of deciduous bonsai, and one really needs to learn to handle and develop them. Use larger pots to extend the time between watering, smaller pots as you approach a display goal (usually a specific date for a show). You can make life easier for yourself by controlling watering interval. Of course weather will interfere, but you can extend or shorten the average time between watering by changing pot size. (within reason)

 

[Leo in N E Illinois]

Desert or arid land origin species for bonsai is its own topic, and yes, we should develop it. I'm talking about drought tolerant trees, not cacti or succulents. My only experience is with Bursera. Others should chime in. Portulacaria afra is another that is accepted by many, but rejected by some as "not tree like enough".

 

[JoeWilson]

Desert or arid land origin species for bonsai is its own topic, and yes, we should develop it. I'm talking about drought tolerant trees, not cacti or succulents. My only experience is with Bursera. Others should chime in. Portulacaria afra is another that is accepted by many, but rejected by some as "not tree like enough".

Succulent vs tree is an odd distinction to try to make. There are many forms of succulent trees. Bursera fagaroides, being a caudiciform, is a succulent, for example.

Anyway, I agree, there are a lot of plants that fit this criteria that are interesting for bonsai.

 

[amcoffeegirl]

I’m a big fan of mame, shohin and tiny leaf plants in general.
One of the secrets to great tiny trees is finding species with already tiny leaves.
This is one of my favorite all time minis-

Cotoneaster by Morten Albek.
There are many great examples of high quality minis these days.
View threads by @maria kapra or @jeremy_norbury to see some nice smaller sizes!
What was the original question again?
I grow ficus and choose shohin as my easy to manage smallest size.
I may try to start a couple mame again.

 

[Attmos]

I’m a big fan of mame, shohin and tiny leaf plants in general.
One of the secrets to great tiny trees is finding species with already tiny leaves.
This is one of my favorite all time minis-
View attachment 612737
Cotoneaster by Morten Albek.
There are many great examples of high quality minis these days.
View threads by @maria kapra or @jeremy_norbury to see some nice smaller sizes!
What was the original question again?
I grow ficus and choose shohin as my easy to manage smallest size.
I may try to start a couple mame again.

Good response. I'm going to attempt mame, but depending on how difficult upkeep is... I may let them grow to shohin size.

 

[amcoffeegirl]

Good response. I'm going to attempt mame, but depending on how difficult upkeep is... I may let them grow to shohin size.

This photo popped up on my FB memories today from 2018. All the pots that I had collected with no plants in them. I have probably double that now.

 

[zens]

The smallest ive seen was kept for over 3 years by a gent who kept in in an old film container as a mini greenhouse. Was a fabulous little tree and he took it most places with him i believe.

 

[oranjeaap]

Just thinking out loud here. I see a lot of people here and elsewhere saying watering is an issue. So why not make some kind of setup with a slow, continuous drip? I've used stuff in a lab for titrations that was cheap and easy to use. Actually I gave myself an idea there for something that would look pretty neat on a bookshelve.

 

[rockm]

Just thinking out loud here. I see a lot of people here and elsewhere saying watering is an issue. So why not make some kind of setup with a slow, continuous drip? I've used stuff in a lab for titrations that was cheap and easy to use. Actually I gave myself an idea there for something that would look pretty neat on a bookshelve.

Been around for years. Expensive and can be cranky but there are many many different kinds of home drip irrigation systems around

https://www.dripdepot.com/drip-irrigation-kit-for-raised-bed-gardening-kit-size-ultimate

 

[Attmos]

Just thinking out loud here. I see a lot of people here and elsewhere saying watering is an issue. So why not make some kind of setup with a slow, continuous drip? I've used stuff in a lab for titrations that was cheap and easy to use. Actually I gave myself an idea there for something that would look pretty neat on a bookshelve.

I'm too new to answer that but I have seen a few people talk about their system. I've run a few drip-systems and like Rockm says, they can be cranky.
If you set one up, make sure to keep an eye on the flow because they seem to just stop dripping sometimes for no apparent reason. Takes some work to dial in the right amount of water too.

 

[ralfish]

Great topic. I might be able to add some useful info (or not). I have a couple dozen little trees in development at the 3 inch and under size. Many smaller even. During the summer months in Vancouver BC (8B) I keep most of them on gravel filled trays with water coming to near the top of the gravel and the pots sitting on top of that. Its important to keep the watering hole out of the water; capillary action will do the rest. They get watered daily: the tray keeps them from drying out and keeps them humid. Im experimenting with the size of the gravel. Smaller seems better but not really sure other than its easier to keep the pots upright (birds and racoons can be a PITA) on 3-5mm pebbles than 20mm stones. Too fine and the pots sink into the substrate, which is fine if its only kept damp. I have a lot of small apple trees, cotoneaster, and others. Its good to group by watering need. Most of my minis are less than 5 years in the small pots. I have more in the 3-4 inch size but thats a different topic. Most are still in development so a ways to go. The first three are the same cotoneaster showing trunk, flowering and berries, next three are apple, then a group pic showing a small pebble (zeolite) filled tray, the flowering plant is a ribes sanguineum(pink flowering currant). a little seed grown J maple, the next three are a bit bigger 3-4 inch class: western hemlock (seed grown) J. flowering currant and the last one is another apple. I have so many apples as I was doing a regular grafting fruit tree thing and had a bunch of root suckers i was growing out for root stock. Super vigorous, but maybe not really appropriate for bonsai. I dont know. The leaves have reduced about to 30% of typical size but still need to get smaller. Defoliation works well on them, I just need to see what they can tolerate. I have learned that they do get sun scorched and aphids love the new growth.

 

[Attmos]

Great topic. I might be able to add some useful info (or not). I have a couple dozen little trees in development at the 3 inch and under size. Many smaller even. During the summer months in Vancouver BC (8B) I keep most of them on gravel filled trays with water coming to near the top of the gravel and the pots sitting on top of that. Its important to keep the watering hole out of the water; capillary action will do the rest. They get watered daily: the tray keeps them from drying out and keeps them humid. Im experimenting with the size of the gravel. Smaller seems better but not really sure other than its easier to keep the pots upright (birds and racoons can be a PITA) on 3-5mm pebbles than 20mm stones. Too fine and the pots sink into the substrate, which is fine if its only kept damp. I have a lot of small apple trees, cotoneaster, and others. Its good to group by watering need. Most of my minis are less than 5 years in the small pots. I have more in the 3-4 inch size but thats a different topic. Most are still in development so a ways to go. The first three are the same cotoneaster showing trunk, flowering and berries, next three are apple, then a group pic showing a small pebble (zeolite) filled tray, the flowering plant is a ribes sanguineum(pink flowering currant). a little seed grown J maple, the next three are a bit bigger 3-4 inch class: western hemlock (seed grown) J. flowering currant and the last one is another apple. I have so many apples as I was doing a regular grafting fruit tree thing and had a bunch of root suckers i was growing out for root stock. Super vigorous, but maybe not really appropriate for bonsai. I dont know. The leaves have reduced about to 30% of typical size but still need to get smaller. Defoliation works well on them, I just need to see what they can tolerate. I have learned that they do get sun scorched and aphids love the new growth. View attachment 612978View attachment 612979View attachment 612980View attachment 612981View attachment 612982View attachment 612983View attachment 612984View attachment 612985View attachment 612986View attachment 612987View attachment 612988View attachment 612989

They're beautiful. So, are you crushing the media you get, down to 3-5mm... or do you buy it that way?

 

[ralfish]

They're beautiful. So, are you crushing the media you get, down to 3-5mm... or do you buy it that way?

Thanks. The zeolite is that size ( its avail locally at grainger as an anti slip material for ice in the winter). Other pebbles etc are sifted to size just like our grow media

 

[Attmos]

Zeolite.... Check. I'll look into that too.

 

[blackadam]

regular grafting fruit tree thing and had a bunch of root suckers i was growing out for root stock. Super vigorous

Not exactly smallest size question but seems i have something grown below graft and looks "super vigourous" - this thing is week old..
How can I propagate this thing? Rootstock could be prunus avium or whatever is used to graft Kanzan
Should cut it now and dip in rooting powder, then try to root and hope to overwinter with mother plant in coldframe (or keep it with my lemons indoor in growbox) or wait and let it grow and prune it in summer and then try rooting?
Cherry is my 1st outdoor plant - i got it from like month

 

[Shibui]

Some rough shots of a few small bonsai here this morning. Apologies for the distracting backgrounds.
Most of these are at least 3 years old. A couple of the tridents are closer to 10 years.

Cotoneaster damerii

Some Chinese elms

Japanese maple

Ficus rubiginosa

Buxus harlandii

 

[blackadam]

by any chance have You pogression threads about them from the beggining?
3 years sounds appealing

 

[Shibui]

by any chance have You pogression threads about them from the beggining?
3 years sounds appealing

I doubt that very much. Way too many trees here to keep track of every individual. many fall by the wayside. Only few make it to this level.
I think the youngest of these trees would be the Ficus. Grown from seed the base swells out, giving a sumo style trunk. Unfortunately, they continue to thicken , even in small pots so every few years it will need a larger pot and subsequent increase in size of the tree.
Buxus harlandii is also relatively quick growing. The corky bark makes the trunk look way bigger and older than it really is and small leaves are in scale with smaller size bonsai.

The others are much more difficult. They all have strong, upright growth habit so getting low bends is difficult. Getting taper in the trunk is difficult. Low branches with ramification is difficult. Getting all 3 together does not just add the difficulty factors. It multiplies the difficulty.

I have photos of this trident and the cascade cotoneaster back to 2019

2019

2020

2022

2023


Might be able to find some of the others if I look hard enough