Peat-based soil is an environmental nightmare. Try these alternatives.



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Peat, the ingredient that makes bagged soil light and spongy, comes from wetlands. Often labeled as sphagnum moss or peat moss, it became popular in the 1950s because of its versatility. It can increase the amount of water soil holds onto while also, paradoxically, increasing its drainage ability — creating an ideal environment for nurturing plants. It’s also lightweight and doesn’t degrade or shrink much in pots.

But while it does all of those things, extracting it is problematic because it strips the bogs it comes from of their carbon stores, and hinders their ability to keep storing carbon — both important parts of fighting climate change. The world’s peatlands contain twice as much carbon as its forests, and scientists believe they can hold on to most of that carbon indefinitely, but only if they remain intact.

Over time, these bogs have been drained to grow crops, graze animals and, to a lesser extent, for fuel and horticultural supplies. This poses an issue because it takes millennia for just a few feet of peat to form. Caitlin Petro, a research scientist at Georgia Tech, studies peatlands and the plants in them. “If you go just a little bit down into the surface, it’s thousands of years old,” she says.

The United Kingdom will ban the sale of peat to consumers beginning next year and hopes to prohibit commercial sales as well within the next few years, to curb its use, citing the environmental effects of draining bogs. More countries are following suit. The United States, on the other hand, hasn’t banned the use of peat. But experts say there are plenty of alternatives for gardeners that are just as good — if not better — at nourishing plants.

In-ground growing doesn’t need peat

If you’re growing in the ground, experts say, eliminating peat-based mixes can improve your plants’ health. Peat moss doesn’t foster the microorganisms that plants rely on in nature. And, Petro said it “definitely won’t be releasing a lot of nutrients into your garden, which is what you want when you add any type of soil amendment.”

Try compost instead. Jared Rosenbaum, co-owner of a native plant nursery in New Jersey, suggests composting fallen leaves, vegetable and kitchen scraps, and grass clippings, to name a few. What some treat as garbage, he treats as gold. As an added bonus, turning your organic waste into compost diverts it from landfills, making your garden a carbon sink.

Composting is easier than you think. Here’s how to get started.

If you can’t make your own compost, most garden centers sell bags of it (just make sure to check the ingredients to avoid added peat), and some municipalities offer it free, as long as you’re willing to bring your own shovel.

Peatless pots are possible

There are also alternatives suitable for container gardening. Alistair Griffiths, a professor and director of science and collections at the Royal Horticultural Society, has been growing thousands of varieties of plants peat-free for decades. Using alternatives might take some getting used to, but once you find the right setup, he says, starting seeds and growing any type of plant without peat is “absolutely possible.” And he has a lush vertical garden by his desk to prove it.

A search for “peat-free soil mix” brings up a dizzying array of options: soils with biochar, hemp and wood and paper fibers are just a few. Don’t get overwhelmed by what’s out there, though. Experiment, but try something with just a few plants before going all-in.

Do some research on what has worked for others. One of the most popular peat-free growing media includes coconut coir, a material made from coconut fibers that has similar qualities to peat, but doesn’t take thousands of years to form. Rosenbaum says he has had lackluster results with coir-based mixes when trying to grow large quantities of plants. Many gardeners in the United States also report mixed results because coir varies greatly in terms of the quality and sustainability of manufacturing.

Griffiths, however, points to several high-quality peat-free soil mixes, including coir-based ones, that are available in the United Kingdom (most are not yet available in the United States). Several nurseries he works with use coir and wood-based mixes successfully with all their plants. The government bans there have placed pressure on manufacturers to work closely with plant experts to produce high quality products.

The best option is to make your own potting mix. This is simple, readily available and cost-effective. Mary and Jim Competti, co-founders of Old World Garden Farms in Ohio, developed what they call the “perfect” recipe, which they use for starting seeds and growing established plants in containers. They can also add it back to their compost pile at the end of the season. To make it, mix equal parts compost, pulverized topsoil (you can dig it up from your yard, just make sure it doesn’t have clumps), and a combination of worm castings, spent coffee grounds and perlite (worm castings and perlite can be found at many major retailers and hardware stores). Use this recipe as a starting point, adapting as needed based on what is available.

You’ll want to use a finer mix for sprouting new plants, as young shoots can easily be hindered by larger particles. Seedlings don’t need much in the way of nutrients, Griffiths says, as the seed contains most of the energy it needs. You can either filter your soil mix through a sieve, or try a peat-free mix specifically made for starting seeds.

Mature plants, on the other hand, need more nutrients. Amendments such as compost, coffee grounds, composted manure and worm castings can replace synthetic fertilizers. Additionally, aeration helps grow healthy roots. Including materials such as perlite and pumice, or rice hulls (found at smaller specialty shops, or online retailers), will add air pockets that help roots thrive.

Plants you buy from a nursery will likely have been grown in a peat-based mix. Though largely unavoidable, asking the staff if they offer plants grown in peat-free media can help raise awareness.

Brianna Wilson is a freelance writer in Oregon.

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