The problem with peat

I’ve spend years avoiding peat. 

It makes no sense to me that “harvesters” should drain these precious and fragile ecosystems, going in with heavy machinery to chew up land that has been host to rare and specialized plants and creatures, just so I can try and re-invent a little bit of nature in Huronia.

Bogs, which accumulate peat at the rate of a millimetre a year (that’s one centimetre in 10 years) are also repositories of carbon. When the carbon is exposed, it’s released into the atmosphere as a greenhouse gas.

And although the Canadian Spaghnum Peat Moss Association states that harvested peatlands can be restored to “ecologically balanced systems” within 5 to 20 years, just what sort of system do they mean? Not a bog.

As the Environmental Commissioner of Ontario points out, “fully harvested sites are often rehabilitated for agriculture, recreation or forestry. However, efforts to restore these sites to their original state have generally not been successful. Current research indicates that if the water table can be re-established and the area is seeded, sphagnum moss populations can be re-established, but that it would take thousands of years to restore harvested sites to their original depth.”

In the United Kingdom, the Royal Horticultural Society has asked gardeners to stop using peat.

Its policy is posted on its website and states in part:

“The RHS considers the purchase of peat to be unacceptable for the primary use of soil incorporation and ground mulching; the RHS does not use peat as a soil improver or mulch in its gardens. At its flower shows it bans the use of peat for staging.”

The thing is that we can garden perfectly well without. If you’re a vegetable grower, adding a product with zero nutrients to your soil is a prime waste of money. Use compost or well-rotted manure. 

As for ornamental gardeners, consider that in their natural state, plants, trees and shrubs do perfectly well without “soil amendments.” One reason is that the various plants’ leaves and needles are allowed to fall and break down, providing moisture retention, protection of the roots from extremes of heat and cold, essential nutrients and a dynamic community of soil organisms. In our gardens we remove this natural mulch, often replacing it with grass, that competes for moisture and nutrients. Sometimes we replace it with a purchased mulch that is much less well adapted to our plants’ needs. 

Anyhow, peat is absolutely unnecessary for most of the plants we grow. Some – like rhododendrons or blueberries – need a more acidic soil than we have here. My personal preference is for plants that are adapted to the conditions in which I am growing, and I refuse to have any that require special treatment, be it watering, fertilizing or wrapping in burlap. It’s a big argument in favour of native plants.

In recent years, I have been experimenting with making my own potting mix with compost. sand and other ingredients. I use leaf mould to keep the mix light and open. To produce it, I save my leaves and scrounge other peoples’. I do need to add time – I leave them in a wire container for a year and a half, watering and turning occasionally. Right now, I’m working with leaves from 2010, which have turned into a rich, moist, dark brown humus that I can put through a sieve. One year, I had a load of sawdust – it made a similarly pleasant soil additive after sitting around for a year. 

Unfortunately I wasn’t sufficiently diligent in the fall of 2010 and I don’t have enough leaf mould for all my needs (I use it as mulch in any new planting), so I’ve been scouring the piles at garden centres, looking for peat-free commercial mixes.

Many don’t list the ingredients on the plastic packaging, which I think is new. If it doesn’t say, assume that it contains peat, the RHS advises. That leaves slim pickings. I decided to work with bagged topsoil from Signal, organic black earth from Fafard and organic mushroom compost from Hydro Agri Canada. I’ll add perlite – a volcanic material available from many sources – for aeration and moisture retention. (NB: The perlite is added only when you're making a potting mix, it's not for outdoor use;  and it's not necessary for potting if you have another light material like leaf mould or decomposed sawdust.)

The RHS has a page on peat-free mixes. Peat has been so cheap and easy to use, it will be a hard habit to break. But it's been cheap because we undervalue our environment. Now, the world is losing its wetlands, and the species that depend on them, at an unprecedented rate for a variety of reasons. I think removing ourselves from the list of wetland exploiters is the least we gardeners can do.

Link to Canadian Spaghnum Peat Moss Association  

Link to Environmental Commissioner of Ontario  

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