Gardening Which did an interesting trial, January issue, where most peat free comnposts scored poorly, some really poorly, with nearly all good growth coming from composts based on peat. Which explains why peat is still used. I use West Riding organic compost which is made from recycled peat, sieved out of Yorkshire reservoirs, a water industry waste – but the compost is expensive. You need to share a pallet load with lots of friends, to get a good price….
Which’s best buy in non peat compost was New Horizon multi purpose; worst buy was Miracle-Gro organic peat free.