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.

National Composting Conference


By Jim Hole

In September 2000, Edmonton hosted the 10th annual National Composting Conference. The focal point of the conference was the Jekyll and Hyde nature of compost. So, how do we turn liabilities like dead plant matter, lumber mill waste, and manure into a manageable resource?

Climbing the C:N Tower

Delegates at the conference noted that any material to be broken down must be organic; in other words, it must contain the element carbon. Fortunately, all terrestrial life is made with carbon building blocks, so this is never a limiting factor. What can limit your compostable materials, though, is nitrogen, the same nutrient found in many fertilizers. The carbon:nitrogen, or C:N, ratio was frequently discussed at the conference. Unless the C:N ratio is within the correct range, the breakdown of organic matter comes to a virtual standstill. Ideally, the waste that you are breaking down should have a C:N ratio of 30:1.

Sawdust—a waste product many have tried to compost with frustrating results—has a C:N ratio of 400:1. Sawdust's very low nitrogen count explains why it takes so painfully long to decompose. Grass clippings, on the other hand, have tons of nitrogen, and if added to a pile of sawdust they can help to strike the right balance between carbon and nitrogen.

Moisture Balance

Finding the correct moisture balance is the second big issue in composting. In one presentation, researchers from the Agriculture and Agri-Food Canada Research Centre in Lethbridge explained the difficulty they faced with composting feed lot manure. Initially, the moisture level in manure is excessive, but after a few short weeks of hot, dry winds, the composting manure becomes too dry for proper decomposition. Whether the compost is too wet or too dry, the breakdown process slows down to a crawl. In back yards, the scale is smaller but the problem can often be the same. Ideally, compost should feel like a moist sponge that's just been wrung out. If your compost is too dry, simply water it. If too wet, turn it with a pitchfork to expose as much of the material as possible to the air.


Finally, remember that compost should never be allowed to get too heavy or dense; this, too, will hinder decomposition. Regular aeration of the compost pile is critical, and easily achieved by turning the pile with a pitchfork once a week.