My garden exploded last year and I know exactly why. The spinach, arugula, kale and radishes, especially, were out of control. I promised my fellow plot gardeners that I’d reveal my secret this spring. Ready? Biochar.

This ancient soil addendum, once used by pre-Columbian Amazonians, is a solid material obtained from the carbonization of biomass. Ancient civilizations would dig deep trenches, fill them with food and agricultural waste, burn the waste then cover it with soil. The practice of ‘Pyrolysis’ involved the use of very high heat and low oxygen, today produced in specialized capsules. The result? Biochar: a carbon dense, porous, rich, dark and charcoal filled soil.

Studies are showing that this amazing soil amendment helps to absorb and hold water, nutrients, toxicity, in addition to increasing carbon storage. The soil acts as a carbon sink to help absorb our over-abundance of Carbon Dioxide that we humans emit. Hefty roots, higher plant yields, less water usage water and carbon absorption – amazing!

Best yet, a single application of biochar lasts for many years. Home gardeners need less than 10% in the top six inches of soil, often mixed with compost. This includes pots! Mix it in with your hands or a small rake. Fortunately, farmers are starting to catch on to the secret, too. Where to buy it? Most gardening stores carry it and we’re also fortunate to have GoBiochar (www.gobiochar.org) in the area. My secret has been revealed and I can’t wait for the next summer 2022 explosion. 

By Mary Closser