Biochar FAQs

Biochar Basics

Improved Soil Structure: Biochar can improve soil structure by increasing its water-holding capacity and aeration.
Nutrient Retention: It can help retain nutrients in the soil, reducing nutrient runoff and fertilizer needs.
Enhanced Microbial Activity: Biochar can provide a habitat for beneficial soil microorganisms, which can enhance plant growth.
Reduced Soil Acidification: It can help neutralize acidic soils and maintain optimal pH levels.

Carbon Sequestration. By storing carbon in the soil, biochar can help mitigate climate change.

Soil Amendment: Mix biochar into your garden soil before planting.
Top Dressing: Apply a layer of biochar to the soil surface as a mulch.
Potting Mix: Incorporate biochar into your potting mix for container gardening.

Biochar can be expensive to buy. Fortunately you can make your own biochar in your backyard while enjoying your Biochar-Making Fire Pit.

Making Biochar

The Biochar-Making Fire Pit prevents air from entering from the bottom of the fire pit which allows biochar to form without being completely burned up. Its tapered shape allows enough air to come in from the top to keep the fire burning.

With the Biochar-Making Fire Pit making biochar takes similar skills as using any fire pit. There is slightly more skill involved to feed the fire and let it burn down but it is simple enough to successfully make biochar on your first try.

We included a bottom up quenching pipe to make quenching biochar cleaner (virtually no ash dust like when quenching from the top) and to allow the quench water to be easily and cleanly drained through your garden hose.

The Biochar-Making Fire Pit features a top-down airflow design that creates a powerful vortex. This mechanism draws smoke back into the flame to be re-burned, resulting in a significantly cleaner and more efficient fire.

Biochar Storage - Application

You can make biochar any time of the year. Just check with your local authorities to make sure backyard fire pits are allowed and avoid making biochar when the fire danger is high.

Biochar, assuming it doesn't catch on fire, will stick around for more than 1000 years so you can store it as long as you want. Inoculated biochar also does not have a shelf life so it can be stored also as long as you want.

Store in an area that does not have the risk of introducing contaminants (E.g. motor oil, plastic, chemicals, etc.) You could simply pile biochar in your garden but if strong winds are a possibility it may be required to cover up your biochar.

Alternatively, you can mix it into your compost pile and allow it to sit until the compost is ready for application in your garden.

Charging Biochar With Nutrients (Inoculating)

If you compost I would add biochar directly to your compost as you make it as long as you are not making so much compost that the biochar exceeds 50% of the volume of your compost pile. After a month in your compost the biochar will have been inoculated with nutrients and microbes giving the biochar (and your garden) a head start for your next growing season. You can add the biochar compost mixture to your garden as you fill up your compost bin. Note that for the long term benefits of biochar (and some of the short term benefits) inoculating your biochar is not necessary.

Composting with about 50% by volume in your compost for a month is an excellent way to inoculate your biochar. This adds nutrients and microbes to the biochar over time and is a free source of nutrients. Other sources of nutrients and microbes include manure, worm castings, worm/compost tea, mushroom soil. Really any source of nutrients and biological activity will help biocharge your garden.

Soil microbes are naturally adapted to local freeze-thaw cycles, possessing a high degree of freeze tolerance. Therefore, if inoculated biochar freezes, the surviving populations will be hardy and well-adapted to your specific climate. However, microbial activity slows down significantly in cold conditions, which, in turn, prolongs the inoculation process.

To dramatically accelerate this 'charging,' inoculate the biochar within an active compost pile. The heat generated by the composting materials sustains elevated temperatures, ensuring high microbial activity and rapid biochar saturation.

Direct application of uncharged biochar provides immediate benefits to your garden, primarily through improvements in soil structure and moisture retention.

For instance, in highly managed environments like raised beds—where nutrient levels are sufficient but rapid drying is an issue—the initial addition of uncharged biochar has shown clear success. Amending the soil with biochar resulted in significantly healthier plant growth (such as tomatoes) compared to unamended control groups, illustrating its quick and positive impact on water management.

However, this strategy changes based on your soil's limitations: If nutrient scarcity (e.g., nitrogen deficiency) is the primary problem in your soil, you will achieve much better results in the first growing season by inoculating/charging your biochar prior to application.

If your plants are primarily constrained by existing nutrient scarcity, applying uncharged biochar carries a potential risk: the biochar may temporarily immobilize or 'sponge up' some available nutrients (often nitrogen) in the first year. This phenomenon, known as nutrient draw-down, could potentially suppress initial growth.

While our personal experience has not shown adverse effects from uncharged biochar in the first season, skipping the inoculation process means forfeiting the significant growth improvement that charged biochar offers immediately.

Regardless of whether you initially inoculate, your soil's native microbial community will naturally charge the biochar over several years. Once this process is complete, the biochar is fully activated, providing its complete range of benefits—including enhanced nutrient retention and water holding capacity—to your garden for generations.