Lava Rock


Many would say that Lava rock is the perfect Bonsai soil and successful Bonsai can be grown in nothing but Lava rock. 

We recommend using Lava Rock as part of a good Bonsai soil mixture. This will give your Bonsai soil structure and help prevent too much compaction, ensuring your soil is draining well and the roots are not rotting. 

From an aesthetic perspective, Red & Black Lava Rock are the most common of Bonsai soil covers. For anyone trying to achieve a naturally uniform look, look no further than Lava Rock.

We are happy to offer 1 pound bags of Red Lava Rock. (Black Lava Rock - Coming Soon)


Soil (Substrate)

Bonsai soils are usually a mixture of organic potting compost (Pine Bark or Forest Floor), Akadamapumice, lava rock in varying amounts. 

It is important for the soil have good water retention while also draining well, along with very good aeration. The quality of the soil directly affects the health, size and growth of your tree. One of the worst things you can do to your tree is plant it in regular garden soil. Garden soil hardens when it drys and can often lead to a disadvantage when growing a Bonsai. 

Soil mixtures can be purchased here, but given their weight and cost of shipping, you can also easily make your own. 


Depending on the type of Bonsai you're growing, here are the general formulas for successful mixtures. 

Deciduous Tree (Leafy and looses leafs in the fall)

50% Akadama

20% Pumice

20% Lava Rock

10% Potting Compost


Coniferous Tree (Evergreen like Juniper, Cedar)

1/3 Akadama

1/3 Pumice

1/3 Lava Rock


If you are not able to check on your Bonsai's moisture levels daily, add more Akadama to the mix. 

Given how these soils erode over time, repotting every 2-3 years is required. 


Here are some suitable replacements if you cannot find the recommended types of soil.

  • Akadama - fine fired or baked clays, some even recommend cat litter as a substitute. 
  • Pumice - fine crushed aggregates, expanded shale and vermiculite.
  • Lava Rock - This can be replaced with fine gravel or you can also look into purchasing a larger lava rock at a hardware or gardening centre and crushing it. 



One of the best and easiest ways to fertilize your Bonsai, is to add a liquid fertilizer mix when water your Bonsai's once a month during the spring/summer. If your Bonsai looses leaves in the winter there is no need to fertilize it then. If you have a coniferous tree, fertilizing the tree once in the beginning of winter and once in the middle of winter should be sufficient.


Customer Reviews

Based on 4 reviews
Kevin Lewis
Ordered 2 Bonsai

Received my 2 Bonsai along with some soil, pots, tools and lava rocks etc. Everything arrived well packaged and healthy. I've had them about 2 weeks now and they have new growth and look very healthy. Will wait another 2 weeks before planting them in the correct pots and soil. Very happy with the service and the quality of the products. Highly recommend dealing with this company.

ed c (Richmond Hill, CA)
Black lava rock perfect size for soil mix

bought with Akadama and Pumice. it is an ideal soil mix for caudex plants. I usually washed it once before use.

TIM CHEUNG (Langley, CA)
Red Lava Rock

The Red Lava Rock was the perfect size for the base mixture of Bonsai soil.

Unfortunately, you still have to sift it once it is out of the bag.

Mix with 1/4 Akadama, 1/4 Pumice, 1/4 Bark shreds and you have the perfect soil mixture.

Stephen (Cambridge, CA)
Great product

Size of rock was perfect. Plants like it.

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