What Is Peat Moss? And Why You Should Skip It

Gardening and potting houseplants seems relatively straightforward: Place plant in soil, water it, and then it grows. But what is peat moss? This popular base for potting media is more than just a component in a soil mix. “When you are growing a plant either in a greenhouse or indoors, you are growing it outside of its natural environment,” says Christopher Satch, founder and CEO of NYC Plant Help and an adjunct professor at the New York Botanical Gardens. “Soil from the earth contains many bugs, microbes [some good, some bad], and a bunch of other variables. The goal of any media is to mimic soil, without carrying the bugs and bad microbes. Peat moss is used for terrestrial plants both indoors and outdoors. It is spongy and holds enough water without being sopping wet, and is derived from digested Sphagnum moss, making it organic.”

There is a point of confusion, however, because not all moss is the same. “Sphagnum moss is fresh and less processed, whereas peat is from Sphagnum moss that has been digested in peat bogs for thousands of years,” Satch adds. “Technically speaking, because peat takes so long to replace, even though it’s a natural process, it is considered a non-renewable resource.”

Peat moss is naturally slightly acidic and can be used to balance the pH. “Most plants like pH to be about 6.0, and peat tends to be around there, making it ideal,” Satch says. It can also provide much-needed water retention without compacting roots in the container. It’s also sterile—so it won’t attract pests or weeds in the same way—and can be used for many types of plants.

Though peat moss soil is available for an affordable price (typically under $20 for an eight-quart bag), the downside is that it has an environmental cost to the ecosystem. The industry staple may have a detrimental impact, but there still are ways to make your plants happy. See how you can curb the peat moss foot print with these three alternatives. 

1. Peat moss releases carbon dioxide 

The process of obtaining peat moss is where issues arise. “When [peat moss bogs] are damaged or drained, they become a source of carbon in the atmosphere,” says Danae Horst, author of Houseplants For All and founder of Folia Collective, a plant-focused retailer in Los Angeles. 

The peat moss harvesting releases ²²twice as much CO² into the atmosphere every year as the entire airline industry. Because of the environmental damage that can come from harvesting peat, it’s been banned in Europe. What’s more, for most plant owners, peat moss is not something that is native to where they live. Not only does the peat moss have to be harvested, but it is also transported across the globe, creating even more carbon in the environment. 

The alternative: The best peat moss soil alternatives are local. Labels like “carbon offset” and “environmentally friendly” are helpful, but check that is is not shipped to you from the other side of the globe.

Although you may not have too much leverage on CO² emissions, you can curb plastic pollution by being selective. Rosy Soil indoor potting mix, for instance, is peat-free and comes in plant-based plastic for packaging. “Rather than coming from petroleum, where most plastic comes from, it’s coming from used sugar cane,” says Jules Giuliano, lead soil researcher for Rosy Soil, which uses Georgia-sourced biochar that was produced from agricultural waste.

Folia Collective has peat-free soil mixes for different types of plants, getting materials from California and Mexico. They’re also sold in compostable bags that can be sent back to be refilled. “We use the coco coir, fir bark, and then we also use pumice, and then we use worm castings as our nutrient component. It also adds a nice density to our mix,” Horst says. 

To further minimize plastic pollution, opt for terra-cotta or ceramic pots, and plants that have no interest in peat moss. Satch is a fan of epiphytes, such as orchids like Phalaenopsis, Oncidium, Cattleya, Paphiopedilum, air plants, and epiphytic ferns. “They are typically planted in cedar bark chips and Sphagnum—very renewable and environmentally friendly,” he notes.

2. Peat moss is a non-renewable resource

Unlike some of the alternatives, peat moss can only really be used once, at least in our lifetime. “It comes from these peat bogs, which are essentially layers, and layers, and layers of organic matter that’s been decaying over really long periods of time,” Horst says. “Once it’s been harvested, it takes hundreds and hundreds of years for it to regenerate, so that’s not great because once it’s gone, it’s gone, at least for the next several lifetimes.”

The alternative: You may not be able to regrow peat moss, but you can mitigate the damage by choosing where your soil mix comes from. “Compost would be my recommendation as the best alternative,” Satch says. A number of materials can be used instead, including biochar (or biomass, a charcoal-like substance from burnt organic matter) and coconut coir pith (finely ground coconut husks). Do keep in mind that the reason that peat is considered an “industry standard” is because the alternatives may have some caveats. 

“Coconut fiber often is not processed enough to remove the sea salts that a lot of coconut fiber has,” Satch continues. “Sea salts contain sodium, which is instant death to plants. Biochar is sterile, which is nice, but raises the pH to be too alkaline for most plants if you use that as a base.  Additionally, it does not hold on to most plant nutrients very well, thereby leaving your plants with a deficiency.”

To make your own mix, Satch recommends first using compost, then biochar, then coconut fiber—in that order—if one or the other is not available. “Be sure to use clean compost,” he adds. “Sometimes folks chuck bacterial and fungal infected leaves into the compost heap, and that contaminates everything.”

Liz Carlson—owner of Node in Lyttleton, New Zealand, and author of Houseplants and Design: A New Zealand Guide—finds mixing your own soil not only environmentally friendly, but mindful as well. “The base of my go-to houseplant soil is one third cacti and succulent mix, one third orchid bark, and one third rough pumice. This creates a beautiful loamy soil mixture that houseplants love.” 

3. Peat moss impacts other plant life

Harvesting peat doesn’t just affect the peat itself, but also the other plants and animals that rely on the bog for nutrients. “In the process of harvesting peat, usually the entire bog and ecosystem is destroyed, making an unsustainable material,” Carlson says.

The alternative: If you do use soil mix with peat moss, make sure it’s sourced sustainably. That means it should come from places like Canada, where the bogs are managed differently than elsewhere in the world by keeping the majority of them intact. Good Dirt, a North Carolina-based company, uses a recycled peat byproduct from the nation.