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This Zero-Cost, Waste-Eliminating Practice Can Produce Abundant Crops from Healthy, Restored Soils for Generations to Come


Photography by Jasmine A Koster

What is zero-cost, waste-eliminating and can restore soils to fertility to produce abundant crops for generations to come?


Gloria Flora gave a presentation on biochar at the Fourth Annual Inland Northwest Permaculture Convergence. She discussed biochar as a method for producing energy and amending soil from waste products that end up in the landfill.

“This is the Permaculture idea of capturing everything…with the pig, everything but the squeal. With the tree, everything but the shadow,” Flora eloquently puts it.

That’s right. It costs nothing but time, by redirecting precious biomass from the landfill and into our soils.

Before Discussing Biochar – What is Biomass?

Biomass is a term for all the waste products from our urban yards and forests for which we can determine no other use. Two examples of biomass found in abundance are trimmings from shrubs or trees and lumber scraps.

Though biomass can be tossed into a compost pile, many times it ends up in the trash heap. Homeowners who don’t have the space or preference for a giant pile of grass, tree clippings, and garden scraps to rot in their yard can turn it into the much more compact biochar.

So Let’s Talk About Making Biochar- Where Do We Get it?

• First of all, consider what your proposed biomass feeds in nature. Mycelium, insects, and bacteria are just a few examples, but mycelium loves biochar. It’s advised to let some of the biomass (such as leaves and twigs that function as moisture holding, soil protecting mulch), if possible, return to the soil as raw material, and add pieces of biochar in different sizes so that they are digested at different times. Remember, you don’t need much.

“There are ways to get biomass that don’t require doing nasty things to the land,” Flora discloses, and more urban yard and forest waste is produced than forest slash. So it’s often a matter of salvaging what would otherwise go into the landfill. Translation? Free materials.

“Up-cycle whenever possible,” advises Flora, “and use biochar as the last option. For example, if you have a palate, use it as a palate. With rotting straw, you can let it rot, or, turn it into biochar, as long as there’s not a higher use for it.”

How is Biochar Made?

1.Take note of the image below of pieces of firewood, what my grandpa would call kindling, but charred. Observe that they vary in size and are placed within a deep, tapered metal basin, which is wider at the mouth and narrower at the base. When making biochar at home, a basin similar to this one is optimal.

2.The fire must be lit from the top to produce the thermo chemical reaction desired.

3.You will know the quality of the resulting biochar. Some pieces being what you want, and others perhaps not so much, by a few factors:

•Biochar will feel light for its size, like it is full of air.

•It won’t leave much of a sooty residue on your fingers.

•Try testing it with vinegar. Does it fizz much? The vinegar gives you some clues about the pH: ash will raise the pH, and the vinegar will fizz proportionately.

•If it has a high ash content, try leaving rinsing it more or leave it exposed outside to weather.

•It won’t leave much of a sooty residue on your fingers. If you need soap to wash it off, it wasn’t baked at a high enough temperature and may not be good for the soil.

Big, lumpy pieces will act as mulch initially, and then break down. Remember not to add a bunch at once. A small amount will suffice.


Photography by Jasmine A Koster

So, Here are Some Benefits of Amending the Soil with Biochar…..

1. Biochar improves soil texture and damaged soil, sequesters carbon and green house gases, and balances soil PH.

2. Biochar is present in the soil for hundreds to thousands of years, which will benefit your children, grandchildren, great-grandchildren…and so on.

3. Anthropologists discovered soil in the jungle that was long ago amended with biochar, allowing large cities to exist in areas of very poor soil sterile soil….

4. Today, the jungle soil still produces 5X as much food in the “pockmarks” of amended soil than in the surrounding areas.

5. Flora discloses that “It’s affordable, if all you have is a slash pile and a match. Immediate rewards, mid term rewards, long term rewards.” Anyone can make and use biochar and it doesn’t cost a thing.

….As Well as Some Ethical Considerations


Photography by Jasmine A Koster

1. The dangers of vermiculite to our international family: “Where do we get vermiculite? We mine it, but not in this country. Because what comes with vermiculite? Asbestos,” Flora laments. “Why is it ok to ask someone in another country to move vermiculite to get asbestosis? So we can ship it here and use it in OUR soil?”

2.Keeping it local to reduce our carbon footprint: We don’t want to transport biomass very far because it destroys the point if energy is used to produce energy. So we take local biomass and produce local biochar. To quote Flora: “Let’s utilize what we’ve got right here what we call waste…and why not do it ourselves?”

3. Tilling vs. Building Soils: Pulling carbon from the earth and throwing it into the atmosphere upsets the historical natural carbon balance: this is what we’re doing with fossil fuels, and this is the consequence born of tilling, the staple practice of traditional agriculture.

4. Proactively, peacefully building the soil, however, restores balance, sequesters the carbon and enables all life forms to thrive once again.

5. Being Conscious Where Your Biomass Comes From: Flora reminds us that “We do not and should not use animal feed as feed stock for biochar-a bad example of doing so caused a crisis in Mexico, with corn going to Ethynol production, not food.”

Jasmine A Koster

As a writer, I spread the seeds of permaculture throughout the online world. Permaculture is a rebranded agricultural philosophy and group of practices which has its roots in indigenous land management/agroforestry. It emphasizes: working with nature, caring for people, planet and sharing surplus, restoring lost habitat, empowering the community through management of their own resources, and maximizing possible resources within available space. Those operating or transitioning to permaculture systems in rural or urban areas, without much time to galvanize support on the web, can contact me for assistance. Topics I report on include: Indigenous origins of permaculture and acknowledging indigenous ownership of knowledge, modern food forests, making permaculture movements intersectional and accessible, urban gardening, soil building, aquaponics, permaculture, stewardship of the land, importance of diverse and symbiotic ecosystems, tribal land management, cultural revitalization and re-skilling communities, events and movements therein.


  1. Issues with Biochar – You need a lot for full benefit, about 10 percent by volume in a raised bed. Works best with no dig methods – otherwise the biochar ends up blowing away. Seems to be most effective on tropical soils as there is a tendency for these to be low in carbon and are often thin. In temperate zones probably most useful at 10 percent by volume on raised beds for high value crops where increased yield would be very worthwhile. Particularly worthwhile for smaller gardens that only have space for a few raised beds.
    I also like to point out its advantageous to soak biochar in liquid comfrey or other liquid fertiliser to activate it. Using seaweed and mycorrhizal in tandam should also increase the benefit, which can be very long term. I am looking at doing it to areas of my small holding but need £750 for just 600 KG which would only be enough for orchard and raised beds. I imagine it would save more than that in fertiliser and in greater yields over time but still a lot of money for initial investment. Even if farm has plenty of straw or wood for feed stock there needs to be large investment in equipment to start with. So not “free”.

    1. I’ve listed a couple of solutions the the potential problems you mentioned:

      Any amount (under 10% of total soil volume) of matured/inoculated biochar will still help the soil.

      It won’t blow away as long as you apply it in strategic ways like tilling it into the soil, adding it right before/after it rains, wetting/compost tea inocculating or adding it to an existing compost.

      Pyrolysing (burning in the absence of oxygen) wood to make biochar can definitely be done for free using very simple methods, you just have to try and keep the temperature high (above 500°C (930°F)), and prevent the char from getting much oxygen (but still allowing the wood gas to escape or else you might cause an explosion). —Burning in a large cone-shaped pit can limit the amount of oxygen to the char, may produce a high temperature, and will burn clean. —If you usually have a burn pile, just do a Top-Lite (also called the Tom Reed Method) on it and spray with a mist once the fire is fully involved, spritzing off the ash as it forms. Both these methods require that you quench the fire once most of the wood gas has burned off so that you will save the char and prevent it from converting itself into ash.

  2. However if co-operatives could be set up to share equipment and time then this could be reduced, and could be a useful way to use up some agricultural wastes that would otherwise be difficult to compost. Also maybe a way to increase coppicing trees which also has benefits for wildlife and woodland flowers. Finally if timber is planked on site then waste could be turned to biochar for an additional income stream.

  3. In Bungoma Kenya, my colleague Salim Shaban is producing Biochar from the Water hyacinth infesting the (not so) nearby Lake Victoria. He first produces compressed weed briqettes which are used as cooking fuel in a pyrolizing stove that he makes himself (anyone can) . The stove makes charcoal as a byproduct.

    1. Stephen – Most interesting! – How are the briquettes formed; dried & processed? We will in FLA, USA – water hyacinths are a BIG problem here – introduced to the area about 1900 and the plant has been going strong ever since. This could be a viable use for our imported plant problem. Do you have any links on how your associate produces it?

  4. Thanks for this elaborate page. I do object to some of your arguments against the use of vermiculite:

    1: the only vermiculite that was contaminated with asbestos – ever – was that of the Libby mine in Montana. Good thing it is closed. Since then regulations at all the vermiculite mines all over the world are extremely high. As it should have been in the US.
    2: the production of charcoal is much worse for the climat than that of vermiculite. The CO2 production of 400 kg. charcoal lies around 480 kg.
    For vermiculite it is 60 kg.

    I do hope you dive into this info and correct this article. You sure do want your articles to be correct so your readers can trust the info you spread.

    Best regards,


  5. Please do not blame modern vermiculite for what went wrong untill 1990 in Vermont, USA. Things have drastically changed since then. Still, nice to know how biochar can be applied in soil maintenance.

  6. Awesome post and learned a few things I had not read in others over the years. I try real had to introduce Biochar gently to my garden soil. I have also found that “slugs” do not like to cross it.

  7. So in other words, we should be burning our green waste and putting the ash back into the ground… but how is burning this waste and releasing green house gasses into the atmosphere environmentally friendly or in line with permaculture principles? Other countries burn their waste bury it but have been strongly encouraged to cease burning due to the polluting factor.

  8. Charcoal floats in sand. It is useful on sandy soil as it stays in the upper layer, and breaks down slowly. TLUD Top Lit Up Draft cooking fires burn the gases and make charcoal as a by product. I live in Australia where the eucalypt and ti-trees around us are a fire hazard in the summer, so a little clearing up, and a one pot TLUD stove for a single frying pan is part of the garden clean up of leaves and sticks. The charcoal goes into a bucket with rainwater and the bucket is up against a warm wall to grow some algae, then into the compost heap it all goes. Our sand dune cliffs show the charcoal layer in the first 6 feet from coastal fires. A little charcoal in the mix really does help the soil to hold more microbes.

  9. @Jules – charring is different that burning for a few reasons. First the material is not allowed to burn all the way to ash. Ash has very little carbon left, but many types of biochar have between 50 – 80% carbon which is resistant to decay. Also many kinds of biochar production equipment allow for the use of other co-products (e.g. heat for cooking or heating, wood vinegar, syngas). Also many new technologies are much cleaner burning than open air burning which reduces fine particulate matter. I’d invite you to read about some of the cascading uses of biochar found here (

  10. One thing that wasn’t really mentioned (only briefly in one comment) is that (with my still evolving knowledge on the subject) bio char needs to be inoculated with the bacteria and fungi that helps the biology of the soil you are amending.

    It’s purpose is as a container. It’s advantage is that it has such a huge microscopic surface area that it (apparently) can hold more bacteria and good biology per cubic cm than if you just had pure soil. The carbon by itself is just carbon, and may be useful if that is what you have a deficiency of, but otherwise needs some really good – biologically active -compost/tea to inoculate it and thus inject some healthy biology into your soil where it is depleted.

    I have used it and am eagerly awaiting to see the results however it is not the only way to build a healthy soil eco-system. That being said, if you have a waste product, use it! :)

  11. Have been making my own Biochar for some years now.
    I soak then drain it so there is no dust when grinding it finer.
    A big concern for me is the wasted energy.
    I have been trying to find a Pyrolising Rocket Stove but no suitable designs found yet.

  12. The arguments against biochar here are generally pretty poor.

    @Simon – I have no idea where this 10% figure came from, 5kg of biochar on a m^2, which is the maximum recommendation I’ve seen, is absolutely no 10% of the volume of the soil it will be incorporated into.
    @Saskia – The production of biochar has a carbon imprint proportional to what is being burned. In the short term it can have a considerable negative carbon contribution, and in the long term, nearly all wood products end up either burning or rotting anyway. Biochar is ideally made from things already in the waste stream.
    @Jules – Assuming you mean trash incineration, yes, just burning all your trash is bad, but that’s primarily because it releases other toxic chemicals, and heavy metals into the atmosphere, and no so much the CO2. Also, biochar is not ash.
    @Shane – You do not really need to inoculate it in such a fashion, although you absolutely can. It will be colonized naturally. A good bet here would be to mix it in with your compost before adding to your soil.
    @Jack – I’d suggest looking for a different form of stove. The entire purpose of rocket stoves is that they’re designed to completely and cleanly burn the fuel, meaning you won’t get any char left over. You’re essentially asking for a rocket stove designed to do the exact opposite of what rocket stoves are designed to do.

  13. Here in Florida, USA – we have SAND. It might be white sand, black sand or red/ brown sand – but the entire component is sand. No clumping ability at all. That’s the kind of soil that does not have nutrients, as there is minimal organic material that can hold the bacteria which work with the vegetation for food production. We do use the typical organic methods of compost, mulching etc – but unlike further north, those results will completely dissipate in 12 months due to our warm, and wet climate. The same efforts 2 states northward, would last several years. Not here – unless the same amt is added in large quantities and every 3-6 months. For these soils – maybe this this method of biochar might be appropriate as a sustainable agriculture tool. But I still have concerns – to add to designated areas of food productions or designated gardens, the amount of biochar will start to add up in quantities over larger geographic regions. What’s the impact if this becomes popular? We still need to have more conversations about: 1: how to make the charcoal without smoke/pollution( looks like it can be done – saw a few videos – need more coaching here); 2) we need more clear info on what’s leaching through to the water table (if used for large areas); and 3) using bio material – trees, shrubs, etc which normally would be used for layering, compost & mulch – now being burned – that’s a tough one to measure the impact overall at this point.

    Adding something to make a soil fertile for 100’s of years sounds like too good to be true – did the original biochar work because in was done on CLAY soils in the Amazon? I really don’t want people resorting to a quick solution of using charcoal or biochar, and then realizing they’re just participating in a modern version of “slash & burn”….food for thought – hope others continue to post here, so we can hear the various results.

  14. As to the comments of biochar/charcoal adding to polution and more CO2 in the atmosphere, I want to mention that the end effect of composting is similar to fire. Composting is in other words a slow burning and not so hot fire and the resulting gasses, etc., are released over a much longer period.

  15. Some points…

    I don’t recall that the verdict was yet out with regard to ‘biochar’… We humans do like to burn things… but as I’ve mentioned previously, biochar seems a little like monoculturalizing compost.

    As I’ve also mentioned previously, and with links, biochar is not to be confused with terra preta, and it is uncertain we quite fully understand terra preta either, especially how it was made, etc.. …Or the (corporate/political) connections of those who supposedly discovered it for that matter.

    Terra preta appears very site-specific (The Amazon), so appending it everywhere seems to make less sense and seems mindless and reckless.

    As the climate warms, there may be more forest fires, so we will get our charred remains whether we like it or not. Why add to it?

    Apparently, biochar is created and implemented under relatively-specific ways and conditions and it is unlikely that they will be met/honored to the letter by the average Joe. I have previously provided links about this hereon too if recalled. The dust.

    I have not really read about any hands-down good reason to use biochar above and beyond regular organic unburned compost– maybe even in the Amazon– and it therefore seems more like a fad/problem looking for a solution. Ass-backwards, IOW. I have also not seen a valid separation between whether positive results using biochar are not simply from the rest of the other compost. I am unsure we can, since biochar may always be hidden within this inextricable context.

    I am unsure worms can deal with biochar the way they can with unburned compost, nor the obvious removal of the nutrient/compost value once it gets burnt.

    Lastly, humans seem to be doing their darnedest to do pretty much everything wrong on this planet, and this biochar thing just seems like yet one of those things. To think that just because it ends up in the permaculture context it somehow makes sense seems flawed and dangerous.

    Again, another kind of permanent culture is a dead one.

  16. I made a fairly large woodgas burner from 45kg and 30kg has bottles, you could go larger with a 45kg gas bottle in 44gal drum, or similar. It cost the price of welding wire, cutting discs, electricity and ten bucks for the bottles from the tip. Choped untreated softwood pallets into chunks, burned them down then quenched. Two loads made a 20l bucket full of charcoal

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