It was launched by Green & Blacks chocolate founder Craig Sams. But complementary growing media products have been delayed due to the lateness of the season.
Carbon Gold is made from charcoal that is produced by heating woody plant matter using a clean technology that captures up to 70% of carbon that would otherwise be released into the atmosphere. The product was launched at the beginning of March.
Sams said: "Garden centres want to see what the product looks like. There's nothing like it on the market. It's the first opportunity for gardeners to make a personal contribution - if you reward people for keeping carbon in the soil you change the way they grow."
Carbon Gold has been trialled at Riverford Organics in Devon by gardener Mark Diacono, producing a 20 per cent increase in yield, said Sams. The range is Soil Association approved.