5-Step DIY Biochar

Have you heard of biochar? The first time I learned of it was while watching the 2019 documentary film, The Need to Grow (which a Canadian cannabis producer CEO, Tanner Stewart, actually helped produce!).

In it, they developed a free energy-producing pyramid they called the Green Power House; essentially a natural battery. The closed-loop algae-based energy system was invented by Michael Smith to generate renewable energy using algae and to capture and recycle CO2, all while producing a nutrient-rich soil amendment… You guessed it! Biochar.

So, they built these futuristic-looking pyramids, they grew algae inside, and powered the dome with a type of kiln that produced biochar. Amazingly, they used the energy harnessed to power greenhouses and other structures on site.

However, tragically, Smith passed away, and the whole project was dismantled for inconclusive reasons.

Sus? Maybe. But today we’re talking DIY biochar.

Let’s discuss fixing the soil with an ancient fire ritual. Biochar can sequester carbon. It can also improve soil fertility by providing a home for microbes and fixing nutrients with its inherent negative charge. This charge sets it apart from charcoal.

Making Biochar: Don’t Burn Down the Barn!

To make biochar for the garden, you will need proper personal protection equipment (PPE), including eye protection and gloves. You need to have your fire safety dialed in, including a shovel, a hose, and a bucket of sand. Make sure there’s no wind or fire bans in your region when burning!

There are two ways of creating biochar. We’re going to discuss the simple fire pit method. Chances are, if you’ve got a kiln at home, you’re already a seasoned fire steward. If not, use a metal barrel or an open pit. And always keep a water source nearby to quench your fire and never leave your fire unattended.

Yes, Mom. Okay, moving on!

Making Biochar: Getting Started

It’s time to collect your biomass, such as fallen logs, brush and branches, as well as crop waste, like corn stalks. You’re going to heat your organic matter in a low-oxygen environment, called pyrolysis. This helps to keep its carbon structure while offering plenty of surface area for the microbes and nutrients to hang onto. Ash is reactive and will not work the same way!

Backyard biochar steps:

• Build a top-lit fire: Stack your biomass vertically and light a fire that burns from the top down using the cabin or teepee method.
• Watch for the flashpoint: Once your flames are burning steadily and the lower material begins to turn black, reduce airflow.
• Choke the oxygen: This is important! Carefully smother your fire by covering it with a metal lid or a thick layer of soil to stop combustion while preserving carbon. Let it char, don’t let it turn to ash!
• Quench with water: Once the fire is fully extinguished, drench it!
• Crush and dry: Now shovel out your biochar, dry it in sunlight, and crush it. We want small pieces, not powder.
• Time to charge it!

Charging Biochar

Charging is critical. If you put uncharged biochar straight it your garden, it can actually compete with your plants by absorbing and binding to nutrients with its negative charge. So think of this step as inoculating your material with nutrients and microbes that will feed your garden.

You can either soak your biochar in compost tea or worm casting tea for 24-48 hours. As an aside, do not bubble your brew in direct sunlight! Microbes will not appreciate this. You can also try mixing biochar with fresh compost and let it age for a couple of weeks. At this point, you’ve created one of the homesteader’s most prized tools in their kit.

I can attest to this for saving my garden as a novice gardener with otherwise dead soil! I applied biochar and then barley mulched the whole thing for extra protection of the microbe hotel. My stunted plants began to grow, and I had a beautiful harvest that year!

Biochar is one of carbon’s most useful forms.

It does not break down once it’s applied to the soil. Instead, it boosts plant health, increases water retention and microbial life, and further sequesters carbon.

Rather than leaving decaying plant matter on your property to release CO2 into the atmosphere, preserve it as biochar and use it to sequester carbon in the garden while boosting plant vitality.

Try it and let us know if the DIY method was effective and how it impacted your garden’s health!