Microforests are small, densely planted areas containing up to 30 species of native plants. They can absorb 30 times more carbon than conventional plantings, and can be as small as 30sqm – the size of three carparks: feasible for that fallow patch of land in your garden, or as a school project. The forest got off the ground with funding from Nelson City Council’s Environmental Grants Scheme. Working to a low budget the two men have brainstormed ways to use waste materials and DIY skills to their advantage. To condition the soil, Davis and Clarken have devised a way to make biochar, a charcoal-like substance made by burning organic material at high temperatures. As well as enriching the soil for years to come, biochar is carbon negative.