Using biochar old

How to use biochar

Biochar has an incredible ability to trap nutrients in soil. 

Use your biochar to enrich your garden and neutralize unpleasant odours in rubbish and compost bins. You should be able to use all the biochar you produce by mixing it with your compost. This is exactly what the Native Amazonians did and it certainly worked for them! Their system of adding biochar to land cleared for cultivation created vast areas of fertile ‘terra preta’ (black earth), which remains a valuable resource to this day. Read more HERE

Working for your plants

Raw biochar you add to your garden will gradually take up water, filling with nutrients and microbes. In order to do this, biochar initially removes nutrients from your soil, such that it can actually stunt plant growth for a time; rather like a new dam starves a river of water while it fills. ‘Inoculating’ or ‘charging’ your biochar by introducing micro-organisms and nutrients, will allow it to bring immediate benefits to your plants by instantly enhancing your soil fertility. The simplest way to charge your biochar is to mix it with your regular compostable waste.  All the biochar produced by an average household can probably be used up in this way. There is another significant advantage to putting biochar into your compost bucket; it effectively deodorizes it! Unless you empty and wash your kitchen compost bucket almost as soon as you put waste into it, you will appreciate the benefit of this! (You can also add biochar to your regular landfill rubbish to achieve the same deodorizing effect). As your compost decomposes, the biochar will become charged with microbes and nutrients. It will also adsorb some of the methane produced by the decomposing process. (Methane is a far more potent greenhouse gas than carbon dioxide). At the end of the process, you will end up with a supercharged compost for your plants.

How to prepare and charge your biochar

Scrape the biochar from your Tawi stove into a bucket of water. Leave it there for a day. Biochar is hydrophobic (water-hating) when it is made, but you need to make it hydrophilic (water-loving). Soaking it in the bucket of water will achieve this. Your biochar will also need to be crushed before it can be used. After removing it from the water (you can use an old sieve for example), let it drain and partially dry; it should remain slightly damp so that you do not produce lots of dust when you crush it. Put your biochar into an old pot or tin and pummel it with a stick. Crush it until most of the particles are pea size or smaller. Remove any bits that won’t crush readily. You can now store your biochar in a sealed container, (we use an ordinary glass jar with a screw-top lid).

After emptying your compost bucket, sprinkle in some biochar. This will gradually absorb any liquid and deodorize it. Add biochar, along with your compost waste, as you fill the bucket. We don’t add more than a third, by volume; the compost will compact considerably as it breaks down, but your biochar won’t.

By the time your compost is mature enough to apply, the biochar mixed into it will be charged and ready to work for your plants.

If you do use your BBQ frequently and produce more biochar than you can readily mix with your compostable waste, then there are many other ways to inoculate it on a larger scale. 

The resources below provide a good guide:


‘Gardening with biochar’ by Jeff Cox, published by Storey Publishing. (This is a fantastic handbook for anyone serious about gardening with biochar).



The experiment below shows graphically just how good our biochar is at capturing fertiliser compounds for your plants. Soluble Miracle-Gro was passed through two test mediums. The vessel on the left contains plain river sand. The one on the right is the same river sand, mixed with our biochar at a ratio of 25% by volume. Our analysis showed virtually all the compounds within the Miracle-Gro were adsorbed by our biochar. The plain sand retained almost nothing. This is an easy experiment to try for yourself.

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