In 1848, workers constructing the railroad line from Bellows Falls to Rutland, Vermont, found the remains of a mastodon buried 11 feet deep in a Mount Holly bog. One tusk was nearly eight feet long. Seventeen years later, farmhands working a peat bog in Brattleboro struck part of a mastodon tusk that measured four feet long and 18 inches around. It is still on display as a “mammoth tusk” in Brattleboro’s Brooks Memorial Library.
How can Ice Age relics survive in bog peat? Saturated with water, deprived of oxygen, and highly acidic due to the influence of sphagnum moss, bog mats inhibit the actions of decomposing bacteria and fungi. Bogs are ancient landscape features and act as biological time capsules, preserving pollen, seeds, spores, woody plants, and even animals. Nutrients are scarce, so some bog plants supplement their diet by capturing animal food with ingenious mechanisms, including our native sundews (sticky hairs), pitcher plants (drowning pools), and bladderworts (tiny aquatic vacuum cleaners). Charles W. Johnson’s Bogs of the Northeast describes these fascinating carnivorous plants.
Sphagnum moss has been used by humans for millennia. The Abenaki peoples of Vermont and New Hampshire used sphagnum for diapers, poultices, and insulation. Colonists stuffed pillows and mattresses with sphagnum. Some bog peat harbors ancient tree trunks that can still be used for fuel and lumber. Finland, Ireland, Russia, and Belarus burn blocks of peat for heat and to generate electricity. Scandinavian bogs produce a macabre crop—the undecomposed bodies of Iron Age people who were killed and thrown into the mire, as described in The Bog People by P. V. Glob.
Countless peatlands have been drained for agriculture. Today, peat is used for relatively mundane purposes: as a growth medium for seeds and seedlings, as a soil amendment, and to make peat pots. The world’s leading sources of horticultural peat are Canada, Germany, Estonia, the United Kingdom, Finland, and Ireland. The U.S. buys 90 percent of Canada’s peat exports, largely as sphagnum peat from Quebec and New Brunswick.
Like rainforests, peatlands are expansive ecosystems that face numerous threats. Removing peat destroys the habitat and is akin to strip-mining. First, the bog is drained of water by ditching. Then the surface vegetation is stripped away, and the upper layer of peat is “milled” or fluffed up with a harrow. After drying in the sun for several days, the peat is vacuumed up, screened, packed, and shipped.
Far more than just a precious environment is lost when peat is harvested. Peatlands are thought to contain greater reservoirs of carbon than all of the world’s rainforests combined. When peat is mined and burned or used for horticulture, carbon enters the atmosphere and contributes to global warming. In cold regions, peat insulates the underlying permafrost; the frozen ground melts and decays when the peat is removed, releasing still more carbon. Peatlands also produce methane, which is formed by anaerobic bacteria. The overlying layer of plants traps methane until the mat inflates up to eight inches. Mining releases the methane all at once, and methane is a greenhouse gas 20 times more potent than carbon dioxide.
Naturally growing peat accumulates at the rate of 8 to 32 inches every 1,000 years. The 5- to 6-foot drainage ditches made during mining can remove bottom layers that are 9,000 years old – laid down only a thousand years after the bellows of the last mastodon echoed across the land. Still, the peat industry refers to the harvest of peat as sustainable. Although Canadian law mandates that post-production peatlands be restored to “working wetlands,” the peat itself cannot be regenerated in our lifetimes.
Fortunately, there are excellent alternatives to horticultural peat moss. Coir (koy’-er), or “coco peat” is an organic, renewable byproduct from coconut husks whose fibers are used to make mats, ropes, and other goods. The waste husks are composted to create potting soil, soil conditioner, fiber pots, and a hydroponics growth medium. Coir adds organic matter, which improves soil tilth and aeration. It increases drainage in compacted soils and water retention in porous media. Coir pots can be planted because they decompose. Marketed as Crop Circles®, dehydrated disks swell to five times the volume when water is added.
Pine bark mulch is another good alternative for starting seeds and seedlings. Composted bark mulch makes a fertile soil supplement and contains few pathogens.
Organix® makes a product from manure composted anaerobically in a sealed environment, which decreases the methane released into the atmosphere, reduces groundwater contamination, and minimizes nutrients entering waterways. Methane is captured for fuel. The resulting odorless solids, sold as “RePeat®,” are used for horticulture and to make planting pots.
Still, there’s no substitute for the cheapest, most available and environmentally friendly alternative to peat moss: homegrown, composted kitchen and garden waste.