B&Q's own brand composts topped the tables in Which?'s research into the bet composts on the market, but Homebase came bottom of the leader board.
The trial carried out throughout 2009, tested 24 composts. Each compost was purchased four times from different areas of the country to allow for variation between batches. Two trials were conducted, one to test multipurpose and john Innes composts, and one for composts specifically recommended for sowing seeds or growing on young plants.
The seed sowing trial was divided into two strands, an easy-to-grow basil and a tricky petunia. Experts at an independent site sowed 25 basil seeds into 12 pots of each compost. The number of germinated seeds and quality of resulting seedlings was recorded. The same test was carried out with the Petunias.
The three Best Buys in this test were B&Q multipurpose compost, B&Q sowing and cutting compost and New Horizon peat-free grow bag.
The B&Q multipurpose compost was consistently the best performing compost on test. It contains 63% peat, less than ever before, and costs £3.98 for a 70-litre bag making it the cheapest on test as well.
The test for growing on new plants used antirrhinum plugs, because they are sensitive to high nutrient levels, and cabbage plugs because they quickly show nutrient deficiencies. The size and quality of the plants were assessed after six weeks.
Again, B&Q took first and second with its multipurpose compost and John Innes No 2 compost respectively. Westland West+ multipurpose was also named an Best Buy.
The best peat-free composts on test were Westland West+ peat free multipurpose compost and the New Horizon peat-free grow bag
Homebase's multipurpose peat-free compost was named Don't Buy in both tests.