Peat moss improves soil aeration, increases its ability to hold nutrients and water, and adds organic matter to the soil.
It's an ideal amendment for adding to areas intended for lawns, flower beds, and vegetable gardens; pots, baskets and containers; and seeding media. Existing lawns can be "top-dressed" with a mixture of coarse sand and peat moss, especially following aeration
Consisting of the leaves and stems of the sphagnum, peat moss is capable of holding over 10 times its weight in water. It's low in nutrient value, containing only about three per cent nitrogen, but excellent as organic matter. Its pH is between 3.0 and 4.5, making it useful for acid-loving plants such as azaleas and blueberries.
Considering all of its good characteristics, it's disturbing to read articles in gardening magazines and the popular press about the imminent demise of Canadian peat bogs. And, of course, itís always the gardeners who are to blame. There is almost always an attempt to guilt us into using alternate, sometimes inferior, amendments in an effort to be "green."
An initial impulse is to scream that it takes a lot more energy to process and bring a tropical coconut hull product to Canada than it does to harvest our northern bogs. But the crux of the matter is differentiating between the Canadian peat moss deposits and those of Europe.
Peat has been harvested and processed for thousands of years in Europe - mainly as a fuel. In Ireland, peat continues to be used as a fuel - primarily to run electric power plants. Yes, there is no doubt that European peat bogs are being depleted.
But there are more than 113 million hectares (270 million acres) of peat bogs in Canada. Less than 0.02 percent of this area (6000 acres) is currently being used to harvest horticultural peat moss.
What's more, peat bogs are sustainable and after harvest Canadian bogs are being restored to the wetlands they once were.
Members of the Canadian Sphagnum Peat Moss Association have developed strict guidelines in consultation with researchers, conservation and environmental organizations, and Environment Canada. Alberta, Saskat-chewan, and Manitoba have provincial wetland conservation and management policies in place. Other Canadian provinces are in the process of developing these.
Among the CSPMA guidelines are:
A one m depth of peat moss must remain once harvest in complete;
Bogs cannot be prepared for harvest too far in advance;
Reclamation should begin as soon after harvest as is practical;
A buffer zone of original vegetation must remain when bogs are cleared for harvesting;
Drainage systems must be compatible with the restoration of the water table after harvest.
Peat forms at the rate of 1-2 mm per year. It is accumulating nearly 60 times faster than it is being harvested. A study by the North American Wetlands Conserva-tion Council (Canada) indicated that harvested peatlands can be restored within five to 20 years after harvest. With responsible management policies, they are indeed sustainable, for Pete's sake.
Sara Williams, with coauthor Hugh Skinner, is finishing a new book, Gardening Naturally, A Prairie Gardener's Chemical-Free Handbook, to be published in spring, 2011 by Coteau.
