In Britain, there’s a huge pressure on gardeners to give up seed and potting composts (potting soil in the US) based on peat (peat moss). Digging peat for use in the garden is bad from the environment, it destroys valuable habitats. Here’s what the Royal Horticultural Society, which has reduced its peat consumption to 0.7% of all their growing media and soil conditioner, has to say on the issue:
“The RHS believes that the commercial extraction of peat at current rates is environmentally unsustainable as it removes peat at a much faster rate than it accumulates leading to the irreversible destruction of peatlands.
“Many viable peat alternatives exist which are either completely peat-free or of reduced peat content. With improved labelling and information on packaging, gardeners will be able to make more informed decisions about peat alternatives.”
The trouble is, peat makes the best medium for starting seeds (above, cick to enlarge - though we certainly don't need peat pots) and for growing on young plants. Which is why everyone uses it. And now it’s proven that most peat-free composts for starting seeds are a complete waste of money.
Which? Gardening - the highly respected, genuinely impartial magazine produced by the Consumers Association in Britain (similar to Consumer Reports in the US) - recently reported on their tests of seed composts. They tested ten composts intended for raising seeds, six based on peat and four without peat. Not only did the six peat-based composts fill the first six places, but two of the peat-free composts were so bad they were rated “Don’t Buy”.
Of one, Which? Gardening said: “The quality of our plants varied from reasonable to dreadful depending on the bag of compost we’d used. The worst seedlings barely grew at all…”
Of course at the RHS they have some of the finest horticulturalists in the world, they have the expertise, so can grow plants in almost anything! But it’s tougher for the rest of us especially when, as Which? Gardening found, even different bags of the same brand of compost can vary enormously.
However, it’s also worth pointing out that when Which? Gardening tested composts for containers, two out of three of their Best Buy composts were peat-free. That’s great news - but not much help if your seedlings never get to planting size.
In the end, I expect some excellent products to be developed. But this is surely a case where government sponsored research could help gardeners and compost producers alike, for the greater good – the environment in general. The producers themselves have clearly not done much of a job so far - for seed composts anyway.
Oh, and by the way. Fresh sphagnum moss (above right, click to enlarge), the progenitor of peat, collected from the wild for orchids and to line hanging baskets? No. There are plenty of good alternatives that really do work.