With so many factors to consider – pH, nutrients, drainage, water retention and more, it can be overwhelming and difficult to choose which soil to use for your bonsai plants. It can get so hard to navigate this bustling market that many people give up on gardening or are demoralized when bad products damage their plants. Well, no longer! We’ve compiled a list of our top 5 favorite bonsai soil mixtures that are bound to improve the health of your plants. Whether you’re a complete newbie or a certified green thumb, we could all use a little guidance every now and then.
This article will talk you through everything you need to know about bonsai soil, and how to choose the best one for your garden. We’ll also share our favorite products for different criteria such as affordability and organic or not.
In my personal experience, it’s best to do your research first and explore the different options on the market and find out everything about how to care for your plant. If you find out for example, that your bonsai likes moist soil then you’ll want to keep that in mind when choosing the products you chose!
Our top pick for this article is Tinyroots all purpose organic bonsai soil blend which is a small-batch, handcrafted bonsai soil mix suitable for all bonsai and all gardeners. We adore this mixture for a number of reasons. It’s trusty, reliable and it gives results!
- Best Overall – Tinyroots All Purpose Organic Bonsai Blend
- Best Affordable – Birch Seed Soil’s Generic Bonsai Soil
- Best Organic – Perfect Plants Premium Bonsai Mix
- Best for Conifers – Tinyroots Conifer Bonsai Soil
- Best for Tropical Bonsai – Tinyroots Tropical Bonsai Soil
Best Overall – Tinyroots All Purpose Organic Bonsai Blend
This potting soil is expertly crafted by bonsai experts with the needs of bonsai in mind. Therefore meaning it has been formulated specifically for optimum bonsai growth. It is mixed and bagged at the Kaikou School of Bonsai where the staff can carefully control the soil consistency. They combine compost mulch, calcined clay, vermiculite and frit. Another thing we love about this soil is that it has been made with gardeners of all abilities in mind, by combining bonus ingredients into the mix Tinyroots has taken care of the Bonsai, making it easier for you to manage.
We’ve chosen this as our top choice because it was so effective when testing it out. I used this exact soil before for my bonsai and it went from a sad, struggling plant to a thriving one which was putting out lots of growth.
- Material: 100% double-sifted compost mulch, calcined clay, vermiculite and frit
- Price: $15.95 / $29 / $46.95
- Dimensions: 2.25 quarts / 4 quarts / 2.5 gallons
|Retains moisture well between waterings but drains quickly||A little bit pricier than some of the other potting mixes on the market|
|Contains ample nutrients||Comes in plastic packaging which is less environmentally conscious|
|Suitable for beginners||Each bag will only repot one or two bonsai|
|Suitable for seeds and junior plants|
Why Do We Love It?
I’m awarding this potting soil the title of best all rounder, so it’s suitable for every type of gardener! I love this potting mix because it can be easily shipped to your house, it’s ready to use and doesn’t need any kind of pre-treatment. It’s super convenient if you’re a busy person like me! There’s so many advantages with this soil, so in turn it really is worth the money. You can even stretch it further by mixing it with another bonsai soil such as our affordable choice from Birch Seed!
Best Affordable Choice – Birch Seed Soil’s Generic Potting Soil for Bonsai
This bonsai tree soil blend is perfect for all situations. It’s ideal for any type of bonsai. It’s a mixture of premium peat moss and perlite based gritty mix. Even so this mix is much more affordable than some others on the market but is also fast draining and allows for great aeration. It’s packaged and ready to use so the whole process is super simple and no-fuss.
I personally love this particular bonsai soil because I can repot all of my small plants with a bag of this combined with orchid bark and coco coir!
- Material: Peat moss and perlite grit mix
- Price: $11.99
- Dimensions: 2 quarts
|Affordable||Synthetic fertilizer is used|
|Retains moisture well||Peat moss included which is not sustainable|
|Should be mixed with more gritty, chunky soil for drainage reasons|
Why Do We Love It?
This soil is just so simple and easy. It can be used for bonsai but also it’ll be a great choice for any other plants you have for instance. It’s one of those products that does exactly what it says on the tin! I’d recommend using this with some chunkier ingredients as well (such as bark or lava rock), which makes this one of the most affordable bonsai soil options on the market.
Best Organic Potting Mix – Perfect Plants Small Batch Bonsai Soil
This is one of the few organic potting mixes available, and it is going to exceed your expectations. This soil had been recommended to me a lot and I thought I might be disappointed if it didn’t live up to the hype but this product delivered. It is a mixture of pink bark, moss, crushed grit and sand. The bark and sand help to aid in drainage and improve the soil structure by providing a grippy surface that helps to anchor the roots of the Bonsai plants in place. This potting mix has an OMRI certification proving that the soil is completely natural, organic and free from chemicals. This is essentially a certificate from the Organic Materials Review Institute which is an international nonprofit organization. Additionally the processes used in the production of this potting mix are certified non-toxic.
- Material: pine bark, moss, crushed grit and sand
- Price: $14.49 / $22.99
- Dimensions: 2 quarts / 8 quarts
|Made in the USA in small batches||A little bit expensive compared to other choices|
|Contains essential nutrients||Peat moss included which is not sustainable as the bogs it is harvested from contain a huge amount of carbon, the carbon is released when the peat moss is harvested|
|Heavy duty, resealable bag|
Why Do We Love It?
We love that this soil mixture is organic, of course, but there’s so many other reasons we’d recommend it. This soil is mixed with your bonsai’s whole life in mind, it will provide a suitable, long term home for your bonsai. This mix is also suitable for all types of conifer bonsai such as Junipers, Redwoods, Cedars and Pines.
Best Soil Mix for Conifer Bonsai – Tinyroots Conifer Bonsai Soil
Another product from tinyroots (they are big in the bonsai world). However this one is specifically formulated for conifer bonsai such as Junipers, Japanese Black Pines, White Pines, Cedar, Cypress and others too. This potting soil is also expertly crafted by bonsai experts with the needs of bonsai in mind, meaning it has been formulated specifically for optimum conifer bonsai growth. It is mixed and bagged at the Kaikou School of Bonsai where the staff can carefully control the soil consistency. They combine ground pine park and river sand with pumice, slate, horticultural charcoal and lava rock for the optimum growing environment. Another thing we love about this soil is that it has been made with gardeners of all abilities in mind, by combining bonus ingredients into the mix Tinyroots has taken care of the Bonsai, making it easier for you to manage.
- Material: Ground pine bark, river sand, pumice, slate, lava rock and horticultural charcoal
- Price: $15.95
- Dimensions: 2 quarts
|Blended specifically for all conifer tree bonsai||On the pricier side, it’ll set you back about $15 for the soil every time you repot a bonsai|
|Can be used to lighten up heavier potting mixes|
Why Do We Love It?
I love that this soil can be stored away for ages. You just have to roll the top down (I use laundry pegs to secure the toils of my soil bags) and put them somewhere dry. It’s great quality and I feel confident using this soil for my bonsai since tiny roots have over 30 years of expert knowledge!
Best Bonsai Soil for Tropical Bonsai – Tinyroots Tropical Bonsai Mix
Yes – another choice from tinyroots! This brand can’t be beaten when it comes to bonsai soil selections, with this tropical blend having been specifically designed for succulents, cacti and tropical bonsai species such as the Brazilian Rain Tree. This mix is also suitable for Bougainvillea, Ficus and Fukien Tea bonsai amongst many others. The ingredients have been chosen to make this blend chunkier than the conifer and all purpose mixes which suit the needs of a tropical bonsai better. The chunkier aggregate allows for ultimate drainage and aeration. I really love this one because I’ve killed MANY tropical bonsai by using the wrong soil, I just didn’t realize how many types of Bonsai there are, and I had never seen a tropical blend before this one.
- Material: double-sifted organic pine mulch fines, coarse river sand, calcined clay
- Price: $16.95 / $29.95 / $49.95
- Dimensions: 2 quarts / 4 quarts / 2.5 gallons
|Made in the USA||As with many bonsai soils, it’s pricier than regular soil (but worth it)|
Why Do We Love It?
We love the tinyroots products for a number of reasons: expertly crafted, reliable and well thought out, but we also love that they are so convenient. Each one has been double-sifted, hand mixed and bagged in a heavy duty bag so that the mix is ready to go whenever you want to repot your bonsai. Whilst it is on the pricier side it’s worth remembering that bonsai soil doesn’t contain any regular soil, which is a much cheaper ingredient but totally unsuitable for bonsai. In this potting mix your bonsai will stay happy for a long time, meaning you won’t need to repot it as often, or buy soil as often – so it’s an investment that might be suitable for you!
Buying Guide and What You Should Know
The factors to consider when buying a soil mixture include nutrients, ingredients, pH levels, all of which can influence the health and ongoing wellbeing of your bonsai plants. Nutrients in the soil will impact the rate of growth and size of foliage. The pH levels of the soil can impact your bonsais’ ability to absorb the key nutrients it needs.
It’s important to understand why each ingredient is included in the soil mix so that you can make the right decision about which soil to buy. Each ingredient has a purpose such as retaining moisture, improving air flow through the soil or providing a surface for roots to grow on, it’s important for the ingredients to work together to cover all of the bonsais’ needs.
Ground Pine Bark and River Sand
Brings more nutritional benefit to the bonsai.
This is a hard-baked clay from Japan which is produced specifically for the purpose of being used in Bonsai soil mixes. It will start to break down after roughly 24 months. This in turn reduces aeration through the soil, so it should be used in conjunction with well-draining soil. Additionally, it is important to know that akadama must be sifted before use. Although many pre-mixed bags will be sifted and ready to use. As akadama is expensive to import and produce it is often substituted for other clay types, especially in countries that are further away from Japan, where it is produuced.
Pumice is a soft rock which is formed from volcanic eruptions, it can absorb water and nutrients well so it is often used in a bonsai mix to help with water retention.
This is also useful for water retention and it helps to create a suitable structure for the bonsai substrate as roots can’t grow into the lava rock.
Organic Potting Compost
This usually contains peat moss, perlite and sand. It is not suitable to be used for plants alone, especially bonsai, as it retains a lot of water and doesn’t allow for adequate aeration and drainage. However, it can be a great base or additional component for a soil mixture.
Fine Gravel/ Grit
It is key for an aerated soil and a well-draining mix.
prevents soil adjacent to the clay from becoming very dry or soggy as it has a very high porosity allowing for super effective drainage and aeration. It’s not suitable as a stand alone ingredient as it has very low nutrient content but it’s a perfect soil amendment.
From pine or fir trees, the bark will help the soil light which allows the roots to grow
This is commonly the primary component of soil mixes but it’s not normally included in Bonsai potting soils. Peat moss which is harvested from bogs is very water absorbent. The moss absorbs water and then slowly releases it for the roots to soak up, preventing them from drying out.
This also called coco coir this is plant material from the inside of coconut shells, the coco coir helps to stop the soil becoming compressed. Additionally, the coir acts in a similar way to peat moss and absorbs moisture which it then slowly releases. Many soils are now opting to use coco coir instead of peat due to the negative environmental impacts of peat farming.
Perlite helps to prevent soil compaction and keeps the soil light. It is made from mining volcanic glass which is also called perlite. This therefore means that perlite is also a finite resource and is not renewable. Where possible I like to reuse my perlite to be a bit more sustainable but it is not always possible to do so when it has been mixed in with soil.
Sometimes horticultural sand will be added to the soil mixture to help with drainage. The soil also benefits the plant by giving the soil more structural integrity. The sand is easier for the roots to anchor into which is important when the bonsai plants get bigger.
Not all soil will contain wetting agents. However this doesn’t necessarily mean that the potting mixes without wetting agents will be bad. The key factor is whether the soil was packaged dry or semi. Whether it’s damp, dry mixes can be difficult to moisten the first time they are used. This is because of the peat moss as it tends to float on the water instead of absorbing it. In contrast, to counteract this problem, a wetting agent may be added to help the moss absorb the water more easily.
Different Mixes for Different Bonsai
Each bonsai species is unique and has its own set of needs. This can sometimes be quite different to other plants, even ones that look similar, so it is always worth knowing exactly which plant you have and using this guide to help you buy your soil mixes.
Deciduous Bonsai Soil
When looking for a soil to replant your deciduous Bonsais you need approximately:
- 50% akadama
- 25% pumice
- 25% lava rock
Coniferous and Pine Soil
- 33% akadama
- 33% pumice
- 33% lava rock
The difference in these mixes is about water retention, deciduous trees typically prefer soils that retain moisture really well whereas evergreen bonsai prefer slightly drier soil mixes.
Generally, bonsai plants require feeding at least once a week throughout the entire growing season which is early spring to mid/late autumn. As some bonsai lose their foliage they don’t need any fertilizer in the winter. Mature bonsai will require less feeding but it is dependent on species, time of year, size of pot, health of tree and more factors. Just keep this in mind when choosing a soil mix. For example you don’t want to use a soil mixture with added food for a bonsai that will lose its foliage in winter and risk overfeeding.
pH levels are measured from acidic to alkaline on a scale of 0 – 14 where 7 represents the neutral value. Bonsai trees usually need a soil which is fairly neutral, between 6-7 on the pH scale.
When a soil mix is too heavy in clay the pH often falls too far into the alkaline conditions, but this can be easily rectified by the addition of organic matter like dried leaves and composted vegetable scraps.
Most but not all potting mixes will say on the bag what pH the soil is. If the information is not available on the packaging it is very easy to test yourself. You can use a cheap piece of litmus paper which you can get in a gardening center or online to test the pH of your soil.
Why is it important to use potting mix and not just garden soil?
Soil from the garden dries out a lot more quickly than potting soil will. So therefore if you have your Bonsais in a container you would likely need to water your crops 2 – 3 times a day. If the roots dried out then the plant’s overall growth would be stunted. Garden soil is also more likely to become compressed which makes it difficult for the roots to grow and can lead to root rot. A growing mix is better suited for Bonsai in pots because the lava rock and calcined clay help to maintain moisture and prevent soil compression.
Should bonsai soil always be wet?
Bonsai soil should never be completely dry, the roots of a bonsai are very small and fragile, and they’ll die off. The soil should not be always wet but it shouldn’t ever be completely dry. Balance is key!
What size should bonsai soil be?
The best bonsai soil should have particles around 4mm for best drainage.
Bonsai Soil Doesn’t Get Better Than Tinyroots!
Choosing from thousands of products is overwhelming, no matter how much experience you have, so we’ve rounded up our 5 favorites to help you out. Tinyroots all purpose Bonsai soil is the one to beat. It’s got the perfect components to support and nurture any Bonsai from infancy to old age whilst encouraging healthy roots and plentiful growth. Each plant is different so remember to keep an eye out on what your plants might be trying to tell you. If you’ve got a specific bonsai type and you want to accommodate those needs, I’d say go for one of the tinyroots conifer or tropical blends! Moreover, if there’s ever confusion we’re here to help, just leave us a comment and we’ll get back to you!
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