9 November 2012: The UK’s first ever commercial biochar trials with professional horticulturalists have shown that biochar helps to boost root growth, reduces the need to water, improves germination rates and results in stronger, healthier plants which are more resilient to disease and changing weather conditions.
The independent trials were commissioned by Carbon Gold, a Bristol-based company producing a range of Soil Association approved, biochar growing products. Biochar is a form of charcoal that has been used for millennia to improve soil nutrition and growing conditions.
The trials with 19 professional growers across the country also found that Carbon Gold composts – and personal compost mixes enriched with GroChar Soil Improver (90% biochar) – performed as well as, and in some cases better, than peat.
Craig Sams, founder of Carbon Gold and co-founder of Green & Blacks chocolate, will be launching the results at the Soil Association Soil Symposium on Thursday 15 November to an audience of soil experts, farmers and growers.
The results come at a time when Defra is deliberating the report from their Sustainable Growing Media Task Force and deciding the future of growing media, and how to reduce peat, in both professional horticulture and amateur gardening. Biochar is one of the amendments to growing media being considered as an alternative to peat.
A selection of feedback from the biochar trialists:
Fergus Garrett, Head Gardener & CEO of Great Dixter said: “Excellent peat substitute, better than green waste. Would not hesitate to use as part of a John Innes mix.”
Martin Kyte, Field Trials Manager at Rijk Zwaan, said: “I initially started trialling Carbon Gold’s GroChar Composts against a peat-based compost, but the results were so good I stopped the peat trials and progressed solely with propagating in GroChar.”
Jez Taylor, Market Gardener at Daylesford Farm, said: “Switching from our usual compost brand to Carbon Gold has cut water usage by a third. The GroChar compost is less prone to drying out.”
Andy Dibben, Farm Manager at The Community Farm, said: “We immediately found that the Carbon Gold Compost had far better water retention properties. Although it took a little getting used to at first, the GroChar compost required less frequent watering and maintained a much better average moisture content than our usual compost.”
Mark Diacono, author, smallholder, photographer and garden designer at Otter Farm, said: “Despite a rather sketchy year, due to the weather and erratic temperatures, I’ve seen excellent root growth in the seedlings I’ve grown with Carbon Gold Soil Improver, I’ve had to water less and it also works well in my own compost mix.”
 The Soil Association Soil Symposium is a two-day technical event dedicated to informing and inspiring farmers and growers on the latest thinking and developments in relation to soil management. Find out more at www.soilassociation.org/soilsymposium
 Read more about Defra’s Sustainable Growing Media Taskforce – www.defra.gov.uk/peat-taskforce