Gardening: Compost review

March 4, 2009

which_logo_mar09Compost producers need to up their game in order to produce good quality, peat-free composts that live up to their peat-based counterparts, according to new research by Gardening Which?.

Despite Government targets requiring compost manufacturers to go virtually peat free by 2010, Gardening Which? tests show there is still a way to go before reliable quality peat-free composts are produced. There remains a large gulf between the performance of peat-free and peat-based composts for growing young plants from seed.

compost_mar09New Horizon Organic and Peat Free Grow Bag was the only peat-free compost deemed to be a Best Buy for growing-on young plants.

Variable results in quality between bags of the same compost bought from different parts of the UK meant it wasn’t possible to make any peat-free compost a Best Buy for sowing seeds.

focus_compost_mar09Focus Multi Purpose Peat Free compost was rated a ‘Don’t Buy’, scoring only 8 per cent overall, and performing badly in both the young plant trial and seed sowing trials.

Traditional peat-based compost continued to top all the trials, with B&Q performing best. B&Q’s Seeds, Seedlings and Cuttings compost scored 88 per cent and was awarded Best Buy status in the seed sowing tests, while B&Q’s John Innes No.2 was the top scoring compost in the young plant trial. This was also awarded a Best Buy and scored 83 per cent overall.

Ceri Thomas, Gardening Which? editor, says: “We’ve been testing composts for a quarter of a century at Gardening Which? and we are still astounded by the variable quality of peat-free products. Compost manufacturers really need to up their game if they are going to produce compost that can balance the needs of the environment with the needs of our plants.”