[Plan of Action] Growing for Size in Containers

[zeejet]

This is a long one - apologies upfront. If TLDR, please see the last section (Draft Plan).

After extensive readings through existing threads on this forum and r/bonsai (Reddit), I’m still a bit unclear and apprehensive about how to approach bonsai stock growth/development (size, trunk, nebari, etc). I’m seeking reasonable growth rates in containers (I have a balcony) preferably with relatively simple setups.

I’ve tried to summarize my understanding/assumptions below and would appreciate a fact check where possible. I then propose a draft plan for growing in containers and a few lingering questions.

Core Concepts:

• For overall growth/size, put it in the ground (field growing).
  • With “unlimited” real estate for root growth (which is mirrored in the growth above ground), field growing is the fastest way to build overall mass.
  • Drainage in-ground is more self-regulating - again, due to “unlimited” real estate - with lower likelihood of over or underwatering.
• An oversized pot is NOT a substitute for field growth.
  • A large pot does not drain the same way in-ground soil drains and is harder to balance moisture when oversized relative to the tree.
  • Tends to retain moisture too long and does not allow roots to breath due to lack of wet/dry cycle.
  • Poor moisture balance hinders root development, which in turn hinders overall mass development.
• Use of containers with open boundaries such as colanders, pond baskets, grow bags, and Anderson flats allow roots to grow beyond the periphery.
  • Exposed roots through these openings dry out and are “air pruned”.
  • Air pruning prompts development of finer root structure within the container as the tree is not finding water/nutrients beyond the container in its current rooting strategy.
  • Finer root structures promote foliar mass, which in turn promote overall mass through trunk and branches.
• For nebari development, use shallow containers or other methods for restricting vertical root growth (e.g. ebihara) while encouraging radial/horizontal root growth.
  • To promote radial growth, vertical center roots are pruned each repotting
  • A hard barrier (such as a tile or piece of flat wood) can be affixed to the base of the tree to encourage radial roots to grow outwards by physically restricting vertical root access.
• For growth-oriented soil, some well-draining organic components may be desirable (although not necessary) for slow but consistent nutrient supply in conjunction with regular fertilizing.
  • Pine or fir bark with similar particle size to inorganic components (⅛-¼”).
  • A mix of equal parts pumice, scoria, and pine/fir bark is a potential starting point.
  • Reuse of soil during repot/rootwork (every 2-3 years) possible with removal of broken-down organics and other fines (via sieving) before adding back fresh bark.
  • Transition to complete inorganic mix during late development and refinement.
  • Table below was found on these forums summarizing key soil properties:

Conflicting or unproven concepts/theories:

• Large grow bags may simulate certain traits of field growth
  • Fabric wicks away water at the boundaries to improve aeration and moisture balance
  • Roots are air-pruned when growing beyond the container.
• Pot-in-pot: the tree is planted in a container with open-structure boundaries (pond basket, colander, Anderson flat, grow bag, etc.), then placed atop/within a larger soil mass.
  • Roots are allowed to continue growing beyond the container into the larger pot but the core root mass is contained for easier management and rootwork.
  • Another approach is to use inorganic soil in a grow bag (drainage and aeration) that is then surrounded by organic soil in a larger pot for moisture retention.
• Light/water/nutrient management is just as, if not more, important than root real estate
• Coarser/aggregate soil promotes nebari while finer soil promotes feeder root development.
  • Feeder roots improve overall mass while larger roots contribute to the nebari.

Lingering Questions:

• Do shallow vs deep containers actually matter (if you diligently prune vertical roots or use the ebihara technique)?
• How much does the minutiae of specific potting strategies actually affect the outcomes? I’m really seeking to simplify the approach - buying multiple types of containers and soils is a bit overwhelming.
  • Do I need to progress up in pot sizes? Or can I simply stick my trees in a large grow box or Anderson flats with a well-draining soil mix? Drainage seems to be the main issue with container vs field growing isn't it?
  • Am I losing a lot of growth by not placing my Anderson flat on a larger soil mass? If so, can I stack an Anderson flat on top of another Anderson flat (both filled with soil) and secure them together?

Draft Plan:

• Repot currently small/underdeveloped trees (½-¾” trunks) in small pond baskets (7”x7”x4”, 0.9 gallons) to promote growth of fine root network through air pruning
  • Use equal parts pumice, scoria, and pine/fir bark as initial growth substrate.
  • Fertilize regularly throughout the growth seasons and adjust for winter months. Considering adding up to 5% horticultural charcoal for additional CEC but unsure if this is useful if I’m fertilizing regularly and have pine bark in the blend already.
• Repot and root work every 1-2 years depending on vigor of root growth
  • Reuse inorganic soil but sieve for fines and refresh degraded bark with fresh bark
• Up pot to a larger pond basket (10”x10”x5”, 2.2 gallons) when fine root structure exhausts available real estate.
• Repeat until need to up pot again and move to Anderson flats (15.75”x15.75”x5”, 5.4 gallons)
  • May need to move into larger grow box or stack flats if volume is insufficient for further trunk growth
• Grow until trunks are desired thickness (1.5”-3”)
• Transition to fully inorganic soil blend and begin late development.
• Repot into bonsai pot for refinement and display

 

[Wires_Guy_wires]

I’m really seeking to simplify the approach

Says the person who did a cool study on all he wants to do.

My approach is simpler:
Year 1: grow in organic soil, like coco coir with a bunch of perlite. At a 1:1 ratio.
Year 2: plant in shallow container with organic soil to build a nebari and a wide network of feeder roots.
The plant is now an inch tall, because I restricted growth a whole lot, but it's ramified as can be because internode lengths are super short.
Year 3: Repot into bonsai soil or a larger container with the same coir/perlite mix. Deeper containers produce fat running roots, wide containers produce more feeder roots.
Year 4: Eh?
Year 5: Plant in ground or in large containers with coco coir and perlite.
Year 6: Dig up, redo the roots, repot into bonsai soil, is it ready for a pot? Then in a pot it goes.

I prefer progressing in pot size based on growth. A plant that's hardly growing in year one, doesn't need a huge pot (more plants per surface area = wider selection = more choice!). If it lifts itself out of the pot in year one or fills it entirely with roots, I move about half a gallon up in size. Repeat until you're satisfied.

The thing is, you can try and think this out ad infinitum but the best course of action is.. Action. No plant sticks to a plan, and making plans too well thought out will become a huge bummer if the plants don't stick to it: it's a whole lot of work and with a bad payoff that really demotivates, so I try not to plan too extensively.. The guys doing awesome growing operations share very little information because simply put.. There isn't a lot to share. You find a formula that works for you, in your situation and with your tree type, and you're set.
The best junipers I can buy are grown in clay soils, against all bonsai knowledge and common sense. And quite frankly, I don't mind! They're good. They work.

Bonsai soil is a luxury that you need in a bonsai pot. If you plan on using it for growing operations, consider not emptying your bank account and instead spend a couple weeks on learning how to water organics. It will make life a lot easier and it's also way less work for you.

 

[zeejet]

Says the person who did a cool study on all he wants to do.

Fair point sir - I suppose I meant simplifying the container arrangement, but failed to consider how much I've overthought this entire endeavor haha.

My approach is simpler:
Year 1: grow in organic soil, like coco coir with a bunch of perlite. At a 1:1 ratio.
Year 2: plant in shallow container with organic soil to build a nebari and a wide network of feeder roots.
The plant is now an inch tall, because I restricted growth a whole lot, but it's ramified as can be because internode lengths are super short.

Bonsai soil is a luxury that you need in a bonsai pot. If you plan on using it for growing operations, consider not emptying your bank account and instead spend a couple weeks on learning how to water organics. It will make life a lot easier and it's also way less work for you.

This is where I'm getting conflicting advice. I've been told to go mostly inorganic and minimize the use of fine moisture retentive organics peat moss or compost. I figured equal parts pumice, scoria, and bark was a decent compromise.

The main fear at this point is overwatering or suboptimal growth conditions for roots using organic soils but I suppose amending with perlite or other drainage amendments could mitigate those risks. All my nursery trees are in organic mixes (30-50% perlite) currently and it's really hard to water them after they dry out (top soil becomes hydrophobic while deeper soil is still very moist).

 

[rockm]

I really don't know what to do with all of this, but your draft plan has some holes. For instance repotting every one to two years will dramatically SLOW development of most anything from sapling to mature trees. Repotting that often can also eventually kill your trees--been there, done that. To maximize development, you want to delay root work and containerization for as long as possible to maximize top growth and especially trunk development. Using pond baskets and air pruning pots can also slow development with seedlings and saplings that need trunk development. If you don't know how to water, they can also kill your trees if you're inattentive on a hot summer day, or when the winds are blowing.

FWIW, trying to scrimp on soils (reusing ingredients, scrambling for substitute ingredients you THINK will work, etc) can also slow development. I don't know how many trees you're working on, but if it's under 20 or so (or 100 mame sized trees, etc.) , find a decent bonsai soil and use it. It's not that expensive and not a luxury. Soil is the engine that drives the whole hobby. Cutting corners and second guessing is fine when you know what works with what tree will speed development. Species are all different, what works for a pine, will slow down a deciduous and vice versa. If you have a hundred trees and have a piece of land, plant them all out in the regular dirt and let them be for five to ten years.

Also FWIW, I have developed and refined all my trees in containers for the last 30 years. I have no real land to work with other than a 30'x30' townhouse backyard.

 

[zeejet]

First off, thanks for the reply and info.

To maximize development, you want to delay root work and containerization for as long as possible to maximize top growth and especially trunk development.

What is meant by "containerization"? Are you suggesting I leave my trees in their nursery containers until the trunk is ready? What about the nursery soil? Shouldn't that be replaced with something better draining? Or is this referring to bonsai pots?

Using pond baskets and air pruning pots can also slow development with seedlings and saplings that need trunk development.

Does that mean the whole open-structured container technique is solely for ramification? Does fine root network not contribute to faster overall growth?

FWIW, trying to scrimp on soils (reusing ingredients, scrambling for substitute ingredients you THINK will work, etc) can also slow development. I don't know how many trees you're working on, but if it's under 20 or so (or 100 mame sized trees, etc.) , find a decent bonsai soil and use it.

Again, this is where there appears to be little to no consensus. A lot of folks like yourself say I should use a proper bonsai mix while others say I should maintain a fair amount of organics (e.g. 50% draining aggregate such as perlite or pumice, 50% organic such as peat moss, potting mix, or coco coir) for the growing phase. This brings me back to my initial thought of equal parts pumice, scoria and bark as it fits somewhere in the middle (pumice and scoria is dirt cheap here in SoCal).

 

[Eckhoffw]

Hey, thanks for putting all your questions out there.

I’m still pretty new at this, lots of questions, floating around at every turn.
What I have learned so far, is that nothing replaces learning by doing.

Seems you’ve done quite a bit of homework.
Go with your gut, do what works for you in your growing situation.
I think in a balcony situation, using a large mat like bin of Gravel/soil Underneath your trees in pond baskets would be awesome.

How many trees are we talking?
How big of balcony space?

 

[rockm]

First off, thanks for the reply and info.

What is meant by "containerization"? Are you suggesting I leave my trees in their nursery containers until the trunk is ready? What about the nursery soil? Shouldn't that be replaced with something better draining? Or is this referring to bonsai pots?

Does that mean the whole open-structured container technique is solely for ramification? Does fine root network not contribute to faster overall growth?

Again, this is where there appears to be little to no consensus. A lot of folks like yourself say I should use a proper bonsai mix while others say I should maintain a fair amount of organics (e.g. 50% draining aggregate such as perlite or pumice, 50% organic such as peat moss, potting mix, or coco coir) for the growing phase. This brings me back to my initial thought of equal parts pumice, scoria and bark as it fits somewhere in the middle (pumice and scoria is dirt cheap here in SoCal).

Containerization means in a container -- ANY container. Bonsai is bonsai because containers restrict roots. Restricted roots help keep trees small. Restricted roots tend to limit growth. Simple as that.

All this depends on what you want from the tree, what you're willing to put up with and practical matters (storage of all the bulk ingredients and what you can affordably source for instance).

Faster, more substantial growth is best obtained with as little root restriction as possible. That can mean many things--there are no absolute solutions, and there are many ways to do this. Larger grow containers are better than smaller (up to a point) if you want to develop trunks. The ground is the best if you have saplings that require more substantial trunks, better nebari etc. FWIW Nursery soil used for landscaping trees is NOT really soil. Nursery soil is mostly meant as a stop gap for trees destined to be planted in the ground for the most part. It is supposed to be lightweight and provide moisture for a while. It's really not a growing medium for growing plants on. Also, sometimes it's the cheapest stuff the nursery can make since it costs money.

Open sided containers are meant to limit root run and growth. It prevents longer roots from developing, but that means growth overall can be slowed. Using them depends on what you want to accomplish with the tree in them.

There is no consensus on this, as there are many ways to accomplish decent bonsai soil. It's is a time-worn argument. It's never 'solved.' You can't set out a specific formula for the 'best' soil. There isn't one. There are tradeoffs and compromises with everything you use. If you feel comfortable with your pumice, scoria and bark mix, use it. It may or may not work. You'll find out. Good bonsai soil from a reputable seller is likely already proven by use. I made my own soil for years. I found It's not real efficient for the trees, or the budget or storage unless you have A LOT of trees, like dozens or hundreds.

 

[dbonsaiw]

50% draining aggregate such as perlite or pumice, 50% organic such as peat moss, potting mix, or coco coir

Just wanted to add that not all components are created equal. Organics can be bark as well, which imo is a much better choice than peat or potting soil. Pumice and perlite are related inorganics but I always use pumice and really dislike the lightweight nature of perlite.

 

[TrevorLarsen]

This is a long one - apologies upfront. If TLDR, please see the last section (Draft Plan).

After extensive readings through existing threads on this forum and r/bonsai (Reddit), I’m still a bit unclear and apprehensive about how to approach bonsai stock growth/development (size, trunk, nebari, etc). I’m seeking reasonable growth rates in containers (I have a balcony) preferably with relatively simple setups.

I’ve tried to summarize my understanding/assumptions below and would appreciate a fact check where possible. I then propose a draft plan for growing in containers and a few lingering questions.

Core Concepts:

• For overall growth/size, put it in the ground (field growing).
  • With “unlimited” real estate for root growth (which is mirrored in the growth above ground), field growing is the fastest way to build overall mass.
  • Drainage in-ground is more self-regulating - again, due to “unlimited” real estate - with lower likelihood of over or underwatering.
• An oversized pot is NOT a substitute for field growth.
  • A large pot does not drain the same way in-ground soil drains and is harder to balance moisture when oversized relative to the tree.
  • Tends to retain moisture too long and does not allow roots to breath due to lack of wet/dry cycle.
  • Poor moisture balance hinders root development, which in turn hinders overall mass development.
• Use of containers with open boundaries such as colanders, pond baskets, grow bags, and Anderson flats allow roots to grow beyond the periphery.
  • Exposed roots through these openings dry out and are “air pruned”.
  • Air pruning prompts development of finer root structure within the container as the tree is not finding water/nutrients beyond the container in its current rooting strategy.
  • Finer root structures promote foliar mass, which in turn promote overall mass through trunk and branches.
• For nebari development, use shallow containers or other methods for restricting vertical root growth (e.g. ebihara) while encouraging radial/horizontal root growth.
  • To promote radial growth, vertical center roots are pruned each repotting
  • A hard barrier (such as a tile or piece of flat wood) can be affixed to the base of the tree to encourage radial roots to grow outwards by physically restricting vertical root access.
• For growth-oriented soil, some well-draining organic components may be desirable (although not necessary) for slow but consistent nutrient supply in conjunction with regular fertilizing.
  • Pine or fir bark with similar particle size to inorganic components (⅛-¼”).
  • A mix of equal parts pumice, scoria, and pine/fir bark is a potential starting point.
  • Reuse of soil during repot/rootwork (every 2-3 years) possible with removal of broken-down organics and other fines (via sieving) before adding back fresh bark.
  • Transition to complete inorganic mix during late development and refinement.
  • Table below was found on these forums summarizing key soil properties:

Conflicting or unproven concepts/theories:

• Large grow bags may simulate certain traits of field growth
  • Fabric wicks away water at the boundaries to improve aeration and moisture balance
  • Roots are air-pruned when growing beyond the container.
• Pot-in-pot: the tree is planted in a container with open-structure boundaries (pond basket, colander, Anderson flat, grow bag, etc.), then placed atop/within a larger soil mass.
  • Roots are allowed to continue growing beyond the container into the larger pot but the core root mass is contained for easier management and rootwork.
  • Another approach is to use inorganic soil in a grow bag (drainage and aeration) that is then surrounded by organic soil in a larger pot for moisture retention.
• Light/water/nutrient management is just as, if not more, important than root real estate
• Coarser/aggregate soil promotes nebari while finer soil promotes feeder root development.
  • Feeder roots improve overall mass while larger roots contribute to the nebari.

Lingering Questions:

• Do shallow vs deep containers actually matter (if you diligently prune vertical roots or use the ebihara technique)?
• How much does the minutiae of specific potting strategies actually affect the outcomes? I’m really seeking to simplify the approach - buying multiple types of containers and soils is a bit overwhelming.
  • Do I need to progress up in pot sizes? Or can I simply stick my trees in a large grow box or Anderson flats with a well-draining soil mix? Drainage seems to be the main issue with container vs field growing isn't it?
  • Am I losing a lot of growth by not placing my Anderson flat on a larger soil mass? If so, can I stack an Anderson flat on top of another Anderson flat (both filled with soil) and secure them together?

Draft Plan:

• Repot currently small/underdeveloped trees (½-¾” trunks) in small pond baskets (7”x7”x4”, 0.9 gallons) to promote growth of fine root network through air pruning
  • Use equal parts pumice, scoria, and pine/fir bark as initial growth substrate.
  • Fertilize regularly throughout the growth seasons and adjust for winter months. Considering adding up to 5% horticultural charcoal for additional CEC but unsure if this is useful if I’m fertilizing regularly and have pine bark in the blend already.
• Repot and root work every 1-2 years depending on vigor of root growth
  • Reuse inorganic soil but sieve for fines and refresh degraded bark with fresh bark
• Up pot to a larger pond basket (10”x10”x5”, 2.2 gallons) when fine root structure exhausts available real estate.
• Repeat until need to up pot again and move to Anderson flats (15.75”x15.75”x5”, 5.4 gallons)
  • May need to move into larger grow box or stack flats if volume is insufficient for further trunk growth
• Grow until trunks are desired thickness (1.5”-3”)
• Transition to fully inorganic soil blend and begin late development.
• Repot into bonsai pot for refinement and display

I’m going to take a wild guess that you are a “type A” personality. You have done a lot of research and are taking the hobby seriously. I would be shocked if you are not successful with how much effort you are already putting in.

 

[hardtimes]

equal parts pumice, scoria and bark is a good mix, i use it for conifers mostly. its a bit expensive though and i dont think its economical to use if youre going to be growing cuttings or from seeds or want a lot of trees. i would also recommend a sphagnum moss top dressing, many people around here make extensive use of sphagnum moss. i started using a premix soil from a local bonsai nursery for small stuff but anything i plant in it seems to explode in growth. i once read that a granular soil mix is for more refined growth. i also once read that dirt is dirt and that you could growing anything in anything as long as you water right. theres a guy in japan that uses only lava rock. my two junipers that i bought from a local nursery were root bound and had a mass of fine roots and only a few thick roots despite being grown in nursery dirt. so, its up to you to figure what you would like to use. although, deciduous plants would benefit from 100% akadama where you live. using increasingly larger pots seems to be the way to go for growing trunk thickness if you cant plant them in the ground, you could just plant a small tree in a large pot but watering becomes trickier

All Purpose Organic Bonsai Potting Soil - 12" x 12" x 6" box- Also Great for Cactus and Succulent Plants!

bonsai organic bonsai soil, organic bonsai soil base, all purpose bonsai soil, all purpose soil, all purpose, general purpose, general purpose soil, bonsai soil, soil, organic soil, organic, cactus soil, cacti soil, succulent soil, succulents soil

houseofbonsai.com

 

[Shibui]

Do shallow vs deep containers actually matter (if you diligently prune vertical roots or use the ebihara technique)?

Shallow containers are a substitute for diligent root pruning. I get much better results from regular root pruning because I can direct the growth. With the shallow container you just cross fingers and hope the roots grow the correct way.
Deeper containers can give better growth than shallow containers depending how diligently one can water and apply fertiliser.
Sitting one Anderson flat on another is the same as using a deeper container. I can't see any point unless you include some screen between to restrict roots from thickening too much.

Repot and root work every 1-2 years depending on vigor of root growth

I have never had any adverse reaction to regular root pruning. I grow a lot of tridents in the ground and routinely dig and root prune EVERY winter. The trees do not die. They do appear to grow and thicken almost as fast as unpruned trees. I can develop a much superior nebari, root mass and trunk taper with this regular pruning above and below.
Fastest growth does not always equal superior bonsai. Rapid growth can also make any problems worse making some trees unusable for bonsai.
Fastest growth in the trunk development stage also does not mean fastest way to a completed bonsai. After trunk thickening comes healing any scars, branch development and branch ramification. Fast grown unpruned trunks will have large cuts that can take many years to heal over. Essentially you are starting with a large stump so need to grow a new leader for the trunk and then branches and then ramification. From a stump this stage can take longer than the initial trunk thickening stage.
Regularly pruned trees will already have healed over initial chops, will have some bends in the trunk, will have some taper in the trunk. In essence you're already part way through the second phase by the time you've achieved trunk thickness which means quicker to the completed product.

Like most of bonsai you will find little agreement on how 'best' to develop trunks. This often means that all the options suggested will work. Some opinions are formed from very limited experience as few bonsai growers develop large numbers of trees but we all want to contribute experiences, often based on just 1 or 2 examples and with limited comparison with other techniques. Sometimes different things work better in certain climates, soil or growing conditions so one size may not fit all.

Your plan will work. Try it and see how well it works. If you have space set up some side by side tests of different methods and see what works for you.

 

[zeejet]

equal parts pumice, scoria and bark is a good mix, i use it for conifers mostly. its a bit expensive though and i dont think its economical to use if youre going to be growing cuttings or from seeds or want a lot of trees. i would also recommend a sphagnum moss top dressing, many people around here make extensive use of sphagnum moss. i started using a premix soil from a local bonsai nursery for small stuff but anything i plant in it seems to explode in growth. i once read that a granular soil mix is for more refined growth. i also once read that dirt is dirt and that you could growing anything in anything as long as you water right. theres a guy in japan that uses only lava rock. my two junipers that i bought from a local nursery were root bound and had a mass of fine roots and only a few thick roots despite being grown in nursery dirt. so, its up to you to figure what you would like to use. although, deciduous plants would benefit from 100% akadama where you live. using increasingly larger pots seems to be the way to go for growing trunk thickness if you cant plant them in the ground, you could just plant a small tree in a large pot but watering becomes trickier

All Purpose Organic Bonsai Potting Soil - 12" x 12" x 6" box- Also Great for Cactus and Succulent Plants!

bonsai organic bonsai soil, organic bonsai soil base, all purpose bonsai soil, all purpose soil, all purpose, general purpose, general purpose soil, bonsai soil, soil, organic soil, organic, cactus soil, cacti soil, succulent soil, succulents soil

houseofbonsai.com

Thanks for the perspective - I think I've seen enough positive feedback on the pumice/scoria/bark mix that I'm going to try it. Main reason for the bark, at least for me, is CEC and water retention (using open-structured containers makes me nervous about moisture during the summer).

Pumice and scoria are dirt cheap here in SoCal (about $0.50 per gallon at my local spot at 3/8" or 3/16"). Appropriately sized Fir bark is far more expensive at about $5 per gallon. Orchiata pine bark from New Zealand is the priciest ($15-20 per gallon) but the most consistently sized and highest quality - definitely don't need this right now. Overall, I can make the blend for reasonably cheap. 1 gallon for my mix would cost about $2 with fir back or even less if using an alternative to bark. A similar mix from BonsaiJack for example would be $28 for a gallon.

 

[zeejet]

I’m going to take a wild guess that you are a “type A” personality. You have done a lot of research and are taking the hobby seriously. I would be shocked if you are not successful with how much effort you are already putting in.

I'm a scientist by trade and a lot of my tendencies at work carry over into my daily life. While this personality can be helpful in many ways, I'll be the first to admit that I'm someone who regularly over-consumes information while being extremely hesitant to act on it. I always feel like I need more information but I know I need to just do it and see how it goes.

 

[zeejet]

Like most of bonsai you will find little agreement on how 'best' to develop trunks. This often means that all the options suggested will work. Some opinions are formed from very limited experience as few bonsai growers develop large numbers of trees but we all want to contribute experiences, often based on just 1 or 2 examples and with limited comparison with other techniques. Sometimes different things work better in certain climates, soil or growing conditions so one size may not fit all.

Your plan will work. Try it and see how well it works. If you have space set up some side by side tests of different methods and see what works for you.

Thanks for your insight! I’ll likely move forward with the plan and adjust as I go. I can certainly try setting up experiments on a set of cuttings from a hardy species like ficus and see what works best.

 

[TrevorLarsen]

I wish I was more like that I’m sure it pays off often.

 

[hardtimes]

Thanks for the perspective - I think I've seen enough positive feedback on the pumice/scoria/bark mix that I'm going to try it. Main reason for the bark, at least for me, is CEC and water retention (using open-structured containers makes me nervous about moisture during the summer).

Pumice and scoria are dirt cheap here in SoCal (about $0.50 per gallon at my local spot at 3/8" or 3/16"). Appropriately sized Fir bark is far more expensive at about $5 per gallon. Orchiata pine bark from New Zealand is the priciest ($15-20 per gallon) but the most consistently sized and highest quality - definitely don't need this right now. Overall, I can make the blend for reasonably cheap. 1 gallon for my mix would cost about $2 with fir back or even less if using an alternative to bark. A similar mix from BonsaiJack for example would be $28 for a gallon.

Summer around here isnt so bad depending on how close you live to the coast. late summer and fall can be bad because of the santa ana winds. usually in the summer, i would wake up to a heavy layer of dew on everything but not in the fall, it gets pretty dry around here. its repot season now so i would recommend getting started with whichever plans you choose. you'd need some shadecloth for deciduous plants since the sunlight is so intense for most of the year. if you find that soil mix isnt retaining enough water for your liking in summer, chop a layer of sphagnum moss and add it to the surface

 

[zeejet]

Summer around here isnt so bad depending on how close you live to the coast. late summer and fall can be bad because of the santa ana winds. usually in the summer, i would wake up to a heavy layer of dew on everything but not in the fall, it gets pretty dry around here. its repot season now so i would recommend getting started with whichever plans you choose. you'd need some shadecloth for deciduous plants since the sunlight is so intense for most of the year. if you find that soil mix isnt retaining enough water for your liking in summer, chop a layer of sphagnum moss and add it to the surface

Thanks for the info! I'm about 5 miles from the ocean so relatively close with no ocean spray salt issues. We have pretty small temperature swings (10F to 20F differential) as you probably experience yourself.

 

[Shibui]

I can certainly try setting up experiments on a set of cuttings from a hardy species like ficus and see what works best.

Ficus may not be the best species to extrapolate findings to other species. I find that ficus thicken quite quickly even when confined in small pots which may skew your results somewhat.

 

[dbonsaiw]

For instance repotting every one to two years will dramatically SLOW development of most anything from sapling to mature trees.

Can you speak to this a little further. For trees in grow boxes, for example, do you recommend that the tree grows out for a number of years and then replanted? That seems intuitive, but there is a good deal of advice out there encouraging yearly repots to further nebari development. I try not to repot yearly for the reasons you stated, but am always concerned that doing so is allowing my nebari to get away from me. (An irrational fear as I am doing this for too short a time to have any evidence of this).

 

[Srt8madness]

I'm a scientist by trade and a lot of my tendencies at work carry over into my daily life. While this personality can be helpful in many ways, I'll be the first to admit that I'm someone who regularly over-consumes information while being extremely hesitant to act on it. I always feel like I need more information but I know I need to just do it and see how it goes.

We call that "Paralysis by analysis"