Date: Sep 30, 2013 Author: Martha Murdock Source: ellwoodcityledger.com (
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Most gardeners are familiar with peat moss. It is easy to find at any garden center, however, it's not easy to find in nature. Its harvest and use are being questioned as a responsible and sustainable garden practice.
Peat bogs in nature are a great carbon store. The world's bogs, though only about 3 percent of the Earth's surface, hold about 562 billion tons of carbon, sequestering it from our atmosphere. That is more than all the trees on the planet. Healthy bogs also slowly continue to increase their capacity each year.
The world's largest expanse of peat is found in Finland. The majority of sphagnum peat sold in the U.S. originates in Canada, where bogs cover about 11 percent of the country.
Though abundant, few bogs are amiable for commercial extraction. Many are located in Canada's most remote and untouched areas, making it economically unfeasible to mine commercially. Canadian companies are currently mining about 0.02 percent of that available and claim it is regenerating 60 times faster than it is harvested.
Canada has many regulations concerning peat extraction, but many scientists agree that these laws still do not make peat mining sustainable, nor peat lands restorable. Some scientists believe peat lands are as important and fragile as rain forests. Being nature's purifiers, they filter an estimated 10 percent of the global freshwater. Important in flood control, these wetlands are vast wildlife refuges and the biodiversity that implies.
Sphagnum grows remarkably slowly (about 1/25th of an inch per year). With that figure in mind, it will take 3,000 years for new peat to reach the necessary depth for commercial mining. Peat is comprised of the growing and dying of sphagnum moss (or in sedge peat, sedges), which builds layers as the partially decomposed plants sink into the bog or marsh. The submerged plants decompose slowly because of the lack of oxygen. Mining the peat releases greenhouse gases back into the environment.
The British have used peat in their gardens for centuries, yet England has recently passed legislation to slowly eliminate its horticultural use. It is estimated that 98 percent of England's peat lands are depleted, and the Department of Environment, Food and Rural Affairs states that the use of peat commercially shall cease in 2030, and in 2020 for homeowners. This law is a compromise, as previously the regulations had peat use stopped in 2015. The British National Trust, (protecting over 600,000 acres) stopped using peat on its lands, and asks gardeners to follow its lead. Ireland has also made plans to curtail peat mining.
The ways most gardeners use peat would actually be better served with alternatives anyhow. It is not good mulch, being too light. It blows away. Peat forms a crust after being wet, making it hard for water to penetrate, causing runoff, rather than soaking into the soil. It is a poor soil amendment, as it has few nutrients.
Instead of peat, try adding spent mushroom compost, garden compost, green kitchen waste, leaf mold or well-rotted farmyard manure to your soil. They all improve soil structure, add trace nutrients, attract earthworms, and introduce beneficial microorganisms to your garden. For mulching, consider pine needles, wood waste, straw, bark chips, straw or cocoa shells.
For moisture control, the renewable resource, coconut coir fiber, made from the waste of food coconuts, is easy to store, coming in tidy blocks. You just add water. It helps soil absorb and maintain moisture.
A new product, Repeet by Organix, a company in Washington, is a by-product of the dairy industry. A fiber made from manure is processed in an anaerobic digester and converted into a peat substitute. Repeet is not available yet in Pennsylvania, but this product might be a great solution in the future.
Rethink your use of peat. Use it sparingly if you must, but consider alternatives for your garden.
Martha Murdock is a Master Gardener with Penn State Extension -- Beaver County.
