Rooting Around in Peat Moss

Rooting Around in Peat Moss

By Linda Affolder

What you add to your soil can be as important as what you plant in it, and springtime preparation of gardens and beds often involves the addition of peat moss. Most gardeners know the basics and benefits of peat moss:
• It is an organic soil supplement that improves plant growth by increasing the air and water surrounding plant roots.
• It saves water. Peat absorbs and gradually releases up to 20 times its weight in water.
• It improves the physical structure of soil. Peat loosens and aerates clay soil and binds light, sandy soil.
• It reduces leaching. Peat absorbs and slowly releases nutrients present in or added to the soil.
• It is a valuable ingredient in gardening compost, curtailing odours in the compost pile.
• There are over 100 species of moss worldwide.


The peat moss you add to your soil comes from the gradual, incomplete decomposition of sphagnum moss, which accumulates in peatlands (or bogs). The development of peatland depends on a complex combination of climatic and other physical conditions. Generally, peatland forms in very moist and poorly drained environments. When the water table stabilizes and the growth of plant material exceeds decomposition, a layer of organic residue results - fibrous peat moss. This layer is excavated, dried, shredded and pressed into bales.

Of the many species of peat mosses, sphagnum peat moss is the most suited to horticulture because the large cell structure of sphagnum moss enables it to absorb, like a sponge, large amounts of air and moisture. The different species of sphagnum vary in their absorptive capacities but remain substantially higher than any other fibrous peat moss.

Most of the world’s peatlands are found in the northern hemisphere and in particular, Canada and the northern United States. Natural peatland accounts for roughly 12% of Canada’s landbase, covering approximately 275 million acres. This figure represents more than one quarter of the world’s estimated 1 billion acres of peatland and covers an area equivalent to the combined size of Washington, California, Oregon and Nevada.

Peatlands cover 20% of Alberta’s landbase. Due to climactic and geological factors, peatlands are chiefly located in boreal wetland regions and the concentration of peatland resources in Alberta is therefore higher in the northern areas of the province.

The value of peat moss lies in its high absorptive capacity, resistance to decomposition and deodorizing quality and a variety of applications for peat moss have existed outside the garden. Historically, peat moss has been used as livestock bedding, surgical dressing and building materials. In fact, by the early forties several thousand Alberta homes were insulated with peat moss manufactured into an insulating material. Peat moss can absorb just under 6 times its weight in oil and currently sectors of the oil and gas industry use it to clean out oil receptacles and absorb accidental oil spills.

Canadian gardeners have added peat moss to their soil for generations. Prior to the Second World War, however, commercial peat cultivation in Canada was small, although sphagnum peat moss existed in every province. At that time, Canada and the United States imported the bulk of their peat moss from Europe. When the Second World War disrupted and cut off these shipments, the Canadian commercial peat moss industry expanded and established Canada as a substantial and high quality source of peat moss.

Today, Canada is one of the world’s largest producers and exporters of sphagnum peat moss for horticultural use, producing more than 98% of the peat moss imported by the United States. The majority of the production is located in eastern Canada, primarily in New Brunswick and Quebec. Peat production also occurs in Alberta, Saskatchewan, Manitoba, Prince Edward Island and Newfoundland.