You can either mix your own or start by purchasing a basic bonsai soil mix. Today, many hobbyists are using “ soil-less mixes.” This just means they do not contain any earth or dirt. ( Never use dirt from your yard for any potted plants.).

Fast Draining - One of the reasons watering bonsai is so difficult to learn, is the different types of soil bonsai are grown in. When watering, the water should run through quickly and come out of the holes in the bottom of the bonsai pot. Water Retention - No matter the soil content, some moisture must be retained. Some components hold more water than others. Aeration –Space between particles is important. This does not mean “air pockets,” which we always avoid.

It means the mix should not be so fine or wet, that it becomes compacted.Soil Components. Container gardeners and plant nurseries grow in a vast number of soil mixes. Many use a very heavy, wet type of soil to prevent drying out so quickly. That does not mean the plant prefers this type of soil, only that it will survive in it for starter growing purposes. If you purchase a pre-bonsai plant in one of these heavy soils, eventually you will need to remove it.Once we create our bonsai and they are ready for bonsai pots, very heavy, extra fine and/or muddy soils should be eliminated.

The irony in the term “bonsai soil” is that there isn’t really any “soil” in most bonsai soil mixes. Instead, a mix of substrates like crushed lava rock are used which more closely resembles gravel than soil. How to Make Bonsai Soil at Home. The best bonsai soil meets the prerequisites of supporting a miniature tree, which include good drainage, proper aeration, and retention of water. Preparing bonsai tree soil mix is not so difficult, if you know the components to be added according to the plant type and growing environment.

Depending upon the species of plant, it may be done gradually or in some cases it can be done all at once. Always consider the time of year!Remember, when it comes to soil, what someone else temporarily ‘ gets away with,’ may prove to be a killer in the long run.If you decide to make your own bonsai soil, remember all components should be free of dust and be similar in size. This can be resolved with sifting and rinsing. (Dust and very small particles can clog the drainage.)Try using one of each - organic and inorganic.Discover which works best for you and your bonsai. Never repot all your bonsai in a recommended mix, without testing it first.

OrganicSome people use peat moss to add acidity for certain plants. However, it retains a lot of water and should be used sparingly.' Potting soil' from garden centers is a last resort for organics and should only be used with the addition of an inorganic aggregate. If you choose to purchase potting soil, do not buy the cheapest! It will most likely be the wettest and heaviest, which is what you do not want!

You will hear about many seemingly odd materials to add to your mix including ‘chick grit’ (a crushed granite available in farm feed stores) and 'kitty litter' a type of calcined clay, as well as imported a kadama clay.Used properly they all work. Lava rock and pumice are other additions used with good results. Overall, a good mix looks like small gravel!When you purchase a bonsai, the top soil you see may or may not be what it's growing in.

Take a chopstick and dig down a little to determine the actual soil. If any gravel is glued on, remove it immediately for better drainage.Where to Go From Here.

Beginning bonsai as a hobby, fairly quickly you’ll ask yourself, what kind of bonsai soil should I use? Bonsai lovers seem to enjoy discussing (debating) what components of their growing mix they pot their trees in. If you’re expecting one resounding answer, forget it.What bonsai soil to use is a bit of a science. If you want to know what you’re looking for and why, then read on. If you just want a packaged mix you can buy, are my recommendations based on product testing.Make or buy?If you’re getting bonsai soil you’re either buying a packaged mix, or mixing your own bonsai soil. If you just want to know what to buy, try my. I do a comparison of eight popular mixes on the market.If you’d like to understand the concept of what you’re going for, or think you might like to make your own, read on to understand conceptually what you’re looking for.Bonsai Soil or Pre-Bonsai Soil?If you’re new to bonsai, before you go out and buy any soil, ask yourself if you want bonsai or pre-bonsai soil.Bonsai soil isn’t necessary for all stages in a tree’s life.

For many bonsai trees, much of their life is spent in earth, a modified potting soil, or a single component. I use pre-bonsai soil for planting seeds, taking cuttings, or just growing out pre-bonsai.Depending on what you grow, in what stages they’re in, and how many you have, it may make a lot more sense to use some sort of pre-bonsai soil for some of your hobby. As my general personal rule of thumb, I use bonsai soil for trees in bonsai pots and trees after they’ve reached the size I want to start training them.

That’s very personal preference though. I also call pre-bonsai soil a modified potting soil.Some common components that you’ll see in pre-bonsai soil are: compost, perlite, sand, peat, bark, and potting soil. I don’t know of anywhere that you can buy pre-bonsai soil. You just mix your own. See on how to do that.What Should I Look for in Bonsai Soil?Bonsai soil should consider several factors: water retention, pH, cation capacity, product lifecycle, and particle size. I’ll talk about each of them below. For a list of individual components and how they rank you can find data on by American Bonsai.What soil you use should be based on the bonsai itself, its conditions, and personal preference.

For example, an azalea would like a slightly acidic pH, a cypress likes a wetter soil when a pomegranate likes it drier. Small bonsai need smaller particles. The person who cares for the bonsai makes that choice.

The other factors you consider are your climate and care schedule. For these reasons people may pick larger or smaller pots, and different potting mediums.Product Life Cycle (aka Durability)Product lifecycle is how fast something breaks down. Some components naturally breakdown during normal use as a potting medium and others don’t.

Organic components naturally break down in time (like pine bark and Akadama) and inorganic components don’t (like lava). The “best” bonsai soil mixes aren’t either inorganic or organic. It’s a point of preference and need of the particular bonsai in question.Organic materials retain water and can help hold together loose inorganic components.

As they break down in time, organics make the soil mix more compact. The higher the percentage of organics in the mix, the more you have to watch for the soil getting too hard.Inorganics don’t retain much water. Excess water simply immediately drains away. If you tend to overwater your bonsai trees than this is the stuff for you.Most mixes have both organic and inorganic components, but today a larger percentage is allocated to inorganics.  Dungeon crawl card game. Trees that are naturally in wetter conditions, like a cypress, might like a mix that is more organic.

Trees that naturally like dryer conditions, like a juniper, might like a completely inorganic mix.Cation CapacityCation capacity or cation exchange capacity is how well the soil mix components hold nutrients. This is important because without much in the way of cation capacity, any fertilizer you give your trees just sort of washes out the bottom.

If you want to hear the science, bonsai expert Adam Lavigne does a nice explanation of what cation capacity is. The best bonsai soil mixes need to have some cation exchange capacity to them. This is one reason the best bonsai soil mix components are raw and jagged, as opposed to tumbled smooth and finished.pHpH is how acid or alkaline a soil mix is. Some plants like a slightly acidic or alkaline soil mix (for example azaleas like acidic soil). But most plants stay close to a neutral 7, or a soil mix that is very slightly acidic. Lower numbers are more acidic and higher numbers are more alkaline.

The best bonsai soil packaged mixes will have a pH of 7 or possibly around 6.5. If you are looking for something more acidic you’ll either get it from a special mix or by using an acidic fertilizer. Water RetentionWater retention is how well your soil mix stores water for the plant to use later. Lets say you soaked with water one cup full of mulch, and a second with glass marbles and then dumped out all the water. Both components would be wet. But after a short time the marbles will be dry and the mulch would stay wet.

That is because bark holds water and glass doesn’t. This is the same reason world class bonsai aren’t all potted in cheap, evenly sized, pH neutral fish tank rocks.

Because, like marbles, they’d get wet but not hold any water. The best bonsai soil mix will let a bonsai’s roots not sit in water, but also be able to access water when it needs it. Without water retention in a soil mix your bonsai will die. Particle SizeParticle size is simply how big the soil mix particles are. The best bonsai soil mixes will have particles that are fairly consistent in size and not too big or small.

That will give your bonsai access to both water and nutrients but also to oxygen. Particles that are too small can make your mix too wet and rot your roots.That’s why you may see bonsai soil or growing mixes to look like a bunch of really small pebble bits rather than like dirt. The size of particles you buy can also relate to the size of your tree. Most bonsai specimens hover around the middle though.Bonsai soil should be well draining and well aerated. Well draining means water moves through the soil well. Well aerated means air moves through the soil well. These qualities go hand in hand.To see if your soil is well draining, water the tree or soil mix thoroughly until the mix and the pot have absorbed their fill. Wait for excess water to drain.

Then pour one more cup of water in. In well draining soil, the excess water should run through the soil mix and out the bottom of the pot within seconds.Why is Using “Bonsai Soil” So Important? Can’t I Just Use Potting Soil?Bonsai soil is important because you’re growing a living thing in unnatural conditions.Naturally, when it rains the water wets the earth and drains down deep into the soil. When it’s dry and doesn’t rain, plants reach down deeper into the earth to get water stored in deeper soil. Bonsai need more vigilant care than regular potted plants because they’re in smaller pots. It is easy for them to get too wet, or too dry, and they are trapped in whichever condition you put them in. This is also why bonsai pots have holes in the bottom.

Plants need the right balance of carbon dioxide, water, and nutrients to live.Regular potting soil is often problematic because it is too dense and water retentive. That means there’s too much water and not enough air.

What is Bonsai Soil Made Of?Some popular bonsai soil mix components are as follows. One other factor that I didn’t list was weight. It’s not a virtue in the health of the tree, but it does make a difference if you’re trying to carry a large tree if you planted in lava (light) or granite (heavy). AkadamaAkadama is baked clay made in Japan especially for use on bonsai.It’s the substance of choice for Japanese masters. It is organic and will break down into yellowish mud within a year or two, requiring you to repot.

Akadama is a brand name (like Turface). One of the reasons it may be so popular in Japan is that it’s cheap there. It’s all imported and quite expensive. BarkPine bark is used most often in bonsai soil, but other types can be used. An organic material that is good at water retention and adds nutrients when it breaks down. It’s cheap and light.

CharcoalHorticultural charcoal is sometimes used as a small percentage of the soil mix. It helps the plant absorb nutrients and removes impurities or toxins. It also does well in water retention.

Diatomaceous EarthDiatomaceous Earth aka Diatomite or DE is used for several different applications from cosmetics to pest control. DE is dangerous when inhaled. When working around DE dust use a face mask and possibly eye protection depending on how much dust you’re generating. A good article on DE, and on Optisorb, a DE automotive product. DE is a dirty medium, very dusty. But it’s cheap and is one of the components with the highest water retention. DE can be found at automotive shops in large bags.

(Don’t confuse it with Fuller’s Earth which is also at auto shops but you DON’T want to buy). Lava rockRed and black lava rock comes from hardened molten lava from volcanic sites. It’s light weight and is in inorganic that will last forever. With it’s rough jagged surface it’s also good for root development and ramification. PumicePumice is a particular kind of lava rock that cooled capturing bubbles inside it. It has some of the same values as lava: it’s good for root development and ramification, lightweight and will last forever. The most notable difference is that the rocks are slightly rounder, and they are white, where lava is black and red.

PerlitePerlite is cooled lava that was reheated. It’s the little white balls that you see in potting mixes. They sort of look like styrofoam and if you blew on them they’d probably float away. They’re there to improve oxygen circulation and lighten the potting mix. ShaleBasically a rock that can be split into slabs.

It lasts forever though, holds some water, does okay at holding nutrients, and can be a good filler. Turface or Calined ClayTurface is a fired clay product. Fired clays are similar to Akadama, but do not break down as quickly. Turface is for use under golf courses and baseball fields to help aerate the grass.

“Turface” is a brand name, but there are other calcined clay products.You name it and it might be included: peat moss, grit, kitty litter, compost, spaghnum moss, slate, sand, coconut coir, gravel, etc.What kinds of bonsai have different moisture requirements or preferences?. Tropical bonsai: like water as you might guess, plants from tropical humid areas with higher moisture levels like higher amounts of moisture. Some popular tropical trees include ficus, Fukien tea, banyan fig, and jade. Fruiting and flowering bonsai: need plenty of water in their growing period.

Some popular flowering and fruiting trees include bougainvillea and crepe myrtle, which are popular for their plentiful and beautiful flowers, lemon, cherry and orange are popular fruiting options (though lemon and orange are tropical and cherries are not). Coniferous bonsai: like it dry, and prefer inorganic materials. Some popular conifer bonsai include juniper and pines.Though it’s not a type of tree, I’d also again note to consider your location as well. If you live in humid Florida you may choose different potting mix than someone in dry Arizona.

Remember too that moss and some types of components are hard to thoroughly wet. It’s easy to water and the top of the soil looks wet. But just an inch below the surface it’s dry.What Kind of Bonsai Soil Should I Use?Now that you know the theory behind what sort of bonsai soil mix you should use, you can either buy a packaged mix (see for best mixes) or make your own.You can also use your new understanding of what you look for to customize your own mixes.

Lets say that you have a dozen trees. Some trees are tropical, some are juniper, and some deciduous. You could buy a bag of general organic mix and then also some extra inorganic mix that you could throw in to make it dryer. Or you could do the reverse and buy a general inorganic mix and buy some organics to throw in to make it wetter.Last, listen to what other people use and consider it, but don’t be swayed.

You are always going to find someone who grew multiple beautiful bonsai in potting soil. Or soil from the garden. Or whatever. And it works great for them. Much like the health of human beings, the health of trees sometimes defies logic. Sometimes people do things to a tree where it probably shouldn’t survive, and it does. Sometimes we do everything right and it doesn’t make it. There are no guarantees. But when you understand what soil mixes offer and make reasonable choices based on your particular tree you will improve your odds.Thanks for reading.

If you’re new to bonsai drop by my. If you’re not new to bonsai, stop by or. Welcome and I’m glad you’re here.

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