How To Make A Good Bonsai Soil Mix

The Perfect Bonsai Soil Mix

[WATCH VIDEO] How to make a good bonsai soil mix. Excellent breakdown and spot on explanations of soil mixtures. Simple, straightforward, and fully understandable. Yet another well made and presented Bonsai Video. Video and audio slightly off, audio slightly delayed. But this shouldn’t deter understanding presented subject matter.

Great info. It took me almost 1 year to sort out my substrate. I live in Batam, Indonesia.
My mix: 80% lava rock, 10% Perlite & 10% Coco Peat.

I’ve only been doing bonsai for a few months now, and what I’ve learned is that there is no right or wrong and everything is basically an extended experiment.

Bonsai Soil Basics

Video Transcript

what’s up guys and welcome back to the bonsai and youtube channel i’m josh and today i’m going to be showing you how to make the right decisions when you’re putting together your bonsai mix so stick around all right so bonsai soil mixes this might be the number one debated issue in bonsai and as funny as it is most of the time when this has been debated neither person is right nor wrong and this comes down to the different questions that we need to ask ourselves when we’re making a bonsai substrate mix because not every mix is going to be the same for every person for every bonsai plot for every tree for every environment so us as the bonsai artist we need to know a list of things so that we can make an educated decision on what the best mix for that tree is going to be in our yard so what i’m going to do today is i’ve got some notes written down here i’m going to go through these things one by one that i’ve written down for myself that i think is important to tell you guys and then that way hopefully at the end of this video you can go away and hopefully have the confidence to make your own bonsai mix so let’s jump straight into it now the first note that i’ve got down here is there’s two types of bonsai soil that we use and what i mean by this is it’s two types of mix so there’s a mix that we use in development and there’s a mix that we use in refinement and when i say mix i don’t mean you know one part this one part that one part that what i’m saying is in refinement generally we will use a hundred percent organic materials such as peat pine bark uh horse sand whatever it may be all those organic materials that’s what we use in a development mix and we know we use these because they’re very rich in nutrients the mix is a lot more dense so this causes the roots to thicken and elongate and we definitely wouldn’t use that kind of mix in a bonsai pot because with the low gravity column that we got in a bonsai pot that kind of mix would clog up the you know the bonsai the pot um and you’re not going to get the refinement that you want out of that mix either in a bonsai pot now in saying that i’m not saying that you 100 cannot use that in a bonsai plot okay because you can it’s not like you’re going to put you know just regular potting mix in a bonsai pot and your tree is going to die that’s not what’s going to happen at all but it’s not optimal so usually we keep the organic materials for development now once we move a tree into refinement this is when we start looking at our inorganic materials such as our academia pumice lava rock scoria zeolite perlite all these kind of things okay this gives us a lot more control over our tree and the tree’s root system will grow a lot more fine and fibrous but just know that in development fully organic materials in refinement fully inorganic materials now once again i just want to note that there are some people out there that use a mix of inorganic material and all organic materials in their bonsai plots and once again this is okay it’s not wrong i’m not going to tell people who do that that it’s wrong because in their area and the trees that they’re growing that might work perfectly for them so i can’t actually tell them they’re wrong when they’re getting great results out of it but for them to do that they obviously know what they’re doing they know what they’re talking about they know what their trees needs are so they’ve been able to make that decision and their trees are loving them for it so let’s go through some of these things and see how somebody might come to the conclusion of what they need to use in their bonsai mix so i’ve got a bunch of questions that we would need to ask ourselves here and the first one that i’ve got is what is our environment like now what i mean by this is there’s some places where it rains for most of the year there’s other places where it doesn’t rain a lot through the year there’s places where it’s very human and there’s places where it’s very arid now when it comes to these different places you don’t want to be using a mix that’s going to go against that environment so what i mean by that is if you live in a really hot arid area you’re not going to want to use a mix that’s super well draining and doesn’t hold a lot of moisture because your mix is going to dry out really quickly and you’re going to be watering five times a day but if you live in an area that rains all the time then you’re not going to want a bonsai mix that holds a lot of water and doesn’t drain well because you’re going to get the opposite effect your tree’s just going to start drowning so this is where we need to look at our environment and just take into a factor what the weather’s like in terms of temperature where it gets really hot what the conditions like in terms of humidity and also wind wind is a big factor that people look over if you live in an area like a coastal area that’s really windy wind dries out trees really quick and i mean really quick so having a higher moisture retention would be really helpful in that area now there’s other things too like and the these are very nuanced kind of things for people who live in areas that get a real deep freeze or cold during winter things like akadama will break down really quick in these conditions if academic freezes it will break down much quicker than normal and then also too i haven’t had personal experience with this but i have and this is from a source in japan that using things like sans so like kittiu that they use in japan if you have a lot of that in your bonsai mix what happens is it holds a lot of water in the particles and then that water freezes and when it freezes it actually expands the surface area within within the bonsai plot so if you can imagine that substrate almost doubling in size once the water gets in there freezes and expands that happens throughout the whole entire pot the whole thing expands and it just pushes the pot apart okay this is the same effect that when you get cheap bonsai pots in a really cold area because those cheap bonsai pots the clay is very porous the water gets in the pores freezes expands and pushes the pot apart and cracks it that’s why we get pots that crack during winter in really cold locations so just keep those little things in mind we need to know what our environment’s like temperature humidity how much rain there is wind and do you get freezing temperatures okay so the next thing is how often are we around to water now a lot of the people in this hobby nine to five jobs i would say that’s probably 80 percent of people that do bonsai have a nine to five job so if you’re you know and all these things that i’m going to say they all kind of work with each other and interlock with each other so say you’re somebody who is not home all day to water and you live in a really hot arid area you’re in the danger zone there of your trees drying out because you’re not home all day to keep watering them and if your mix dries out really quickly it’s gonna you know your tree will die pretty fast so how often are you home to water can you water once a day twice a day three times a day this kind of thing is going to tell you that if you’re not around you’re going to have to up the moisture retention in your [Music] substrate now something else you can do here is just reposition your tree to a position where it gets a good amount of morning sun and then by the hottest part of the day it’s getting shade whether this might be a 30 shade cloth or if it’s just under the shade of a tree if you watch where the shade moves around your yard of the day you might be able to put your trees in a position where they get good morning sun but shaded of an afternoon but just keep in mind you need to know how often you actually are going to be able to water now the next question you’ve got to ask yourself is what condition do our tree species like now what i mean by this is things like your junipers and pines they can get closer to the dry side of things without being affected too much but there’s other plants like something deciduous in that if they get too dry you’ll see that the leaves will start to wilt and curl up they may even dry out and completely drop off so some of our trees need to maintain a higher moisture level than others while some tree species need to actually dry out a little bit before their next watering because they don’t like their feet to be too wet so you know like here in australia our australian natives they are really really thirsty they love water some of them we can actually keep them in trays of water all throughout summer so with those kinds of trees we would up the moisture retention a little bit more just to keep those trees happy but with our junipers and pines and stuff like that we can bring that moisture retention down a bit more and you yourself can do some research you can look up akadama and what its moisture retention is what its nutrient retention is and you know how long it’s going to last if it breaks down because academic does break down it’s one of our it’s one of the inorganic materials it actually does break down so look those things up look it up for pumice lava rock and all that and then you can make the decision on what kind of ratio you mix these things at if you need higher moisture retention you might put more academia in and less pumice if you need less moisture retention you might put less academia in a more pumice so you can kind of see how changing that mix changes the moisture retention drainage and all that kind of stuff so just go through look at all the different substrates look at the properties that they have in terms of moisture retention drainage nutrient retention all that kind of stuff and then just find out what your species like when they like to dry out a little bit whether they like a lot of moisture present in the soil mix now the next thing we need to ask ourselves and this is an important one that a lot of people look over and is how often do we repot our trees and this isn’t exactly a question of me asking you how often you replot your trees but this is more of a species specific question so say for example here and just i’ll just give you a few examples but we’ve got privets here in australia that we grow as bonsai as i’ve mentioned before you could be repotting them every six months because the root growth is just crazy but let’s just say for argument’s sake once a year for a privet okay most of our deciduous material every two years most of our coniferous materials around five years okay so what you need to ask yourself here is if i’ve got a tree that gets ring pointed at a five year interval i’ve got to have some substrate in that mix that’s not going to break down and take away our balance of water and oxygen because we know for a good mix we need a balance of water and oxygen and what happens and this is what happens really quickly with organic materials and this is another reason why i wouldn’t recommend using them in a bonsai plot what happens is that material breaks down and as it breaks down it suffocates the mix so it makes it a lot harder for oxygen to get into the mix and it holds a lot of water so basically you think about it you’re drowning your tree okay you’ll notice that the the soil will stop percolating so the water will sit on top of the soil surface rather than freely going through so if you’ve got things like you know your coniferous material you’re not going to put them in 100 acadama because akadama breaks down after about 18 months and that’s a really high quality akadama if you get a cheap acadama it’ll break down quicker if you live in an area where you get freezing temperatures it’ll break down quicker so obviously you’re not going to plant them in 100 akadama now i just want to clarify here too because when we’re in bonsai and this is why there’s so many arguments is because there’s so many avenues you might have to use a lot of acadama in your mix with your junipers and pines and all your coniferous material because you might need a higher moisture retention okay but just keep in mind that you’re going to have to repot it every two years and in that case you’re probably not going to get the growth that you’re wanting you’re not going to get that really tight ramified growth by letting the you know tree become really root bound and getting that real tight compact root system so as i said keep in mind the species and how often it’s going to be repotted we’re really lucky here in australia we can use 100 academia on our deciduous and we can use 100 acadama on our natives and this is because they can be repotted within the time that academia will break down academia’s got a really high moisture retention level so those trees love it okay but as we move into other parts of australia that’s not going to be true anymore because some parts they get really freezing temperatures so that academia is going to break down a whole lot quicker other parts of australia they get colder temperatures so that moisture is not going to leave the mix quick enough because it holds a lot of moisture so these things just have to be adjusted and that’s why we’re going through all these questions all right now the next one is what’s available to us not everybody has acadama available to them not everybody has pumice available to them and especially in the particle sizes that we need you can go to a garden shop and get scoria but it’ll be in like 20 ml particle sizes and you’re not putting that in your bonsai pot so you need to look around and see what is available to you and you need to do the best with what you can get okay we don’t live in a perfect world where we can get exactly what we need what we want so it’s just up to you to take all these questions and just look at everything analyze it and see what’s available to you and just do the best with what you can get nobody can fault you for that if you can do the best with what you’ve got and somebody says oh look you shouldn’t be putting that in your bonsai plot and you can say well look i can’t get this i can’t get that this is the best i’ve got i know that i’m going to have to re-pot in this amount of time because of this so you’ll at least be armed with an answer in that case but as i said just do the best with what you can get and then the next thing here is particle size which i just spoke about before so generally when we buy inorganic materials you’ll see them come in so our bags of macadamia here they come in a bag of two to four mil two to six mil and six to twelve mil and then our pumice i believe it comes in three to three to six mil and six to 12 mil um so generally what we do is the bigger and i’m going to really generalize this because i’d be here all day talking about this if i had to go through it all specifically but what we do is generally generally we layer our bonsai soil some people do this some people don’t once again there’s no right or wrong so but personally you lay in your bonsai mix so on the very bottom layer at the bottom of the pot that’s where we have our bigger particle sizes because it creates an aeration layer and a drainage layer so it creates a layer at the bottom of the pot where water can freely run out it’s not going to get all clogged up in the bottom of the pot and also it allows air to come up through the holes in the bottom of the pot and into the mix okay because it’s got that really coarse you know much larger particle size right in the bottom of the pot now in the body of our mix right in the middle this is where we would use our medium size particle particles and now this is medium size against the tree you’re using okay so if you’ve got a little shohen tree you’re not going to use you know 12 mil particle size because that’d be just silly okay you’re going to use a shogun mix you’re probably going to use about four mil particle size in a shogun tree where is in you know chew him tree or in an imperial tree you might be using six mil particle size you might be you know it’s just the bigger the tree gets the bigger the particle sizes get so the body in your mix you’ll use a combination of you know for let’s just say a two-hand size tree for example anywhere between two and six mil um and then on your very top layer that’s where you would use your finest particle and your smaller stuff so probably your two mil your two to four mil two ml is getting really small so i’d only suggest that in your show him stuff but let’s just say two to four mil on your top layer and this will help keep moisture um on top of your mix and stop the moisture from you know evaporating quicker in the in the hotter weather so just use it as like a surface dressing i wouldn’t use the real fine small stuff in the mix itself in the body because you’ll end up clogging it up and as it it’ll break down really quickly and you’ll suffocate your mix really quickly and our last thing here is what are our main objectives in the mix and that is water retention oxygen levels nutrient retention and our drainage okay so we need to look at all these things how much moisture does it retain what are the oxygen levels going to be like because as i said we always want to maintain that batter balance of water and oxygen in the mix we also want the mix to be able to have some capacity to hold nutrients when we fertilize we don’t want the nutrients to just come straight out of the bottom of the pot because it is soluble meaning that it’ll wash out of the bottom of the pot if there’s nothing in there that can actually grab onto those nutrients and have a cation exchange then you know you’re going to be pretty nutrient deficient in your mix so akadama actually has a really good cation exchange so that’s why we love it in the world of bonsai so your nutrient intention and your drainage and you’ve probably heard people say before that if you’ve got a really well draining mix it’s almost impossible to over water your tree and that is true because you can keep watering your tree and it’s only going to hold on to the moist in the pores of the the substrate particles it’ll hold moisture and the tree will grab from that when it needs okay so it’s not going to get all cloggy any excess moisture is going to run out the bottom of the pot because it drains really well the substrate will hold on to a little bit of moisture the tree will grab that when it needs it so you’re not going to get that standing water in the bottom of the pot you’re not going to get waterlogged or anything like that and this is where i see uh beginners ask this question all the time i’m going to have rain for a week straight should i bring my trees inside and the answer is if you’ve got a really well draining bonsai soil mix no leave them out there in the rain let them soak up that you know really nice pure rain water you know the one chance that they get where they’re not getting watered with you know chemical filled town water leave them out there if you’ve got a really good draining mix then there isn’t going to be an issue alrighty so i know that there was no flashiness in that video and no trees but i really hope that for you guys that video was just full of information and now when you go to do a bonsai soil mix if you go through this video again and write down all those points have them on a piece of paper and then when you go to choose a bonsai soy mix you can look at all those things and ask yourself all those questions and then you can look up on the internet akadama how much moisture does it hold what’s its nutrient retention rate pumice lava rock all that kind of stuff look it all up and then you can make a good decision for you specifically because once again i can’t stress this enough if you go on facebook and ask people what bonsai soil should i be using and they give you an answer don’t listen to it because they didn’t ask you what temperature does your environment get up to what’s your humidity like how much wind you get how often you’re around to water what species are you working with how deep is your bonsai plot all this kind of stuff so there’s no possible way they could have given you a correct answer the only way that you’re going to get a correct answer from someone is if it’s joe blow that lives next door he’s got really good quality trees you go over and you say hey joe blow what soil do you use and he’s going to be able to give you a really good suggestion because he lives right next door in the same environment as you chances are you guys have the same species trees and you’re getting the plots from the same spot so that’s probably the only time that you can get really good advice other than that when it comes to substrate you really need to learn these things and be able to make your own decisions and that is based on your trees your environment and what’s available to you but i’m going to stop rambling on now and let you guys get back to your bonsai work once again i’m josh from bonsai and don’t forget to share like and subscribe as that really helps this channel and until next time enjoy your bonsai journey

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