Key Points
Peat moss is popular in gardens because it holds water, adds air to soil, and keeps nutrients from washing away.Harvesting peat moss harms slow-growing peat bogs, releases carbon, and damages fragile wetland habitats.Swapping out peat moss helps the planet by protecting carbon-storing peat bogs and the animals that live there.Easy alternatives like compost, leaf mold, and coco coir work just as well without hurting the environment.
Peat moss is a common ingredient in many bagged potting mixes and garden soils. Gardeners love it because it helps with moisture retention without causing fungal issues. Despite its popularity, there are many negative consequences of using peat moss in the garden. Peat moss is harvested from peat bogs, which releases carbon dioxide into the atmosphere and can disrupt the plants and animals living in the bogs. Here, our gardening experts break down exactly how peat moss is used, the problems it creates, and the alternatives to consider instead.
Ondrea Kidd, lead floral designer and founder of Sowing Joy Farm in Post Falls, Idaho
Ward Dilmore, founder and head landscape designer at Petrus Landscaping, a luxury and estate landscaping business
Lindsey Chastain, founder and CEO at The Waddle and Cluck
Garrett Benisch, director of design development for Bioforcetech, which specializes in transforming waste into carbon-negative solutions
What Is Peat?
Peat is the partially decaying matter of sphagnum moss, an aquatic plant that grows on the surface of waterways and wetlands. “As the plant grows, it creates a carpet of sorts that supports its own ecosystem,” explains Ondrea Kidd, founder of Sowing Joy Farm. “As the plant matures, the bottom foliage dies and sinks to the bottom of the wetland, creating the layer of peat that is harvested for gardening.”
Peat forms very slowly, creating the base of an important ecosystem. “Since I was born 33 years ago, peat bogs around the world have grown in height by just over one inch—not exactly regenerating at the rate we need to be able to harvest it without an impact,” says Garrett Benisch, director of design development for Bioforcetech.
Why Gardeners Use Peat
Peat is easy to find in hardware stores and garden centers, says Ward Dilmore, founder and head landscape designer at Petrus Landscaping. “It can be confused with compost and other beneficial organic amendments for amateur gardeners,” Dilmore says. “When gardeners have poor soil or have a difficult time watering their plants, they often turn to peat. It’s also commonly added to soil mixes when purchasing bagged soil and amendments to help with water retention.”
Peat stays moist for extended periods, adds airspace to soil to prevent compaction, and maintains nutrients in the soil because it doesn’t let water drain away as easily. “When you put those behaviors together, you get a pretty knockout soil additive,” Benisch says. “I certainly don’t blame someone loving peat without knowing the impact of taking it out of the bog.”
Cons of Using Peat in the Garden
While peat can be useful in the garden, it sometimes does more harm than good. Plus, our experts note that it can be more expensive than other organic amendments.
Repeat use could be problematic: Your soil is an ecosystem, and it requires a good balance of amendments to maintain an ideal growing environment. “Adding peat year after year could eventually turn your garden into a peat bog itself,” Dilmore cautions.Only beneficial in its best form: If peat dries out, Benisch warns that it can become hydrophobic and turn very brittle. “If you then try to water it, you may end up draining your soil of nutrients and be left with less organic matter to promote life,” he says.Alters soil chemistry: Peat is a very acidic additive that can change your garden’s soil chemistry if used excessively. While some plants like acidic soil, many do not, Dilmore says.
The Environmental Impact of Harvesting Peat
Although peat bogs cover a tiny fraction of the planet, they store a lot of carbon. In fact, they store twice as much carbon as all the world’s forests. According to Benisch, flora and fauna eat, live, and die in these environments, creating a buildup of organic matter over time. “As this activity layers up and the peat grows over each layer, the carbon of all that life gets covered and held nice and tight,” he says. When peat is harvested, it is cut and peeled back, releasing carbon dioxide into the atmosphere.
Harvesting peat can also be devastating to the wildlife that lives in these ecosystems. Peat bogs are home to plants and wildlife, including insects and animals. When the peat is harvested, these ecosystems are disrupted, and because the peat bogs regrow so slowly, the depletion of some plant and animal species can be devastating and permanent, says Kidd.
Alternatives to Peat
It can be difficult to find pre-mixed bags of soil that do not contain peat as an ingredient, Kidd warns. “Many countries, such as Ireland and England, have already begun phasing out and ceasing the use of peat,” she says. “But the U.S.—although beginning to become aware—is still using a lot of peat.” If you’d like to stop using peat, consider some of the alternatives below.
Homemade Compost
Compost is made from green (nitrogen-rich) and brown (carbon-rich) material. “Toss in leftover vegetables, egg shells, coffee grounds, tea bags, and other organics,” says Lindsey Chastain, founder and CEO at The Waddle and Cluck, adding that you should avoid adding meat or anything greasy or oily. Turn your compost regularly and keep it moist for a few months, and you have the perfect peat replacement, she says.
Leaf Mold
Leaf mold is a partially-composted mix of leaves and other organic materials that Kidd recommends using instead of peat. “This addition can help aid in soil aeration, moisture retention, and add good nutrients,” she says.
Aged Manure
Aged manure might be a little tougher to get, but it can usually be found at nurseries. “It adds nutrients to and improves the texture of the soil,” Chastain says. “You just want to make sure it has been aged long enough so it doesn’t burn the plants with its high acidity.”
Coco Coir
Coco coir is a natural fiber harvested from the coconut husk and behaves like peat in soils. “What’s even easier about coco coir is that its pH is neutral, so no need to worry about throwing off the balance in your soil,” Benisch says. The only downside is that it has to be shipped overseas.
Biochar
Biochar is black carbon made from organic materials like wood, nut shells, or organic waste. “The way it’s made causes the carbon in these organics to get locked up in tight bonds, meaning it won’t break down for centuries into carbon dioxide,” Benisch explains.
There are many biochar mixes on the market for soil, but Benisch recommends Rosy Soil. “It has taken the lead on eliminating peat in all their mixes with the perfect blend of biochar for their product,” he says. “When you take this route, you say no to carbon-emitting, ecosystem-disrupting peat and then you say yes to carbon-storing, waste-reducing biochar.”