If you make your own potting mix or seed-starting soil blocks, your recipe probably requires at least some peat moss. In fact, myriad gardening books and magazines still praise peat for its ability to retain moisture and improve soil texture. The ingredient certainly has its benefits, but we’d all be better served by leaving more of this natural resource undisturbed.
“If we weren’t in the state that we are with our climate, I think [using peat] wouldn’t be quite such a negative thing,” says Briana Bosch, owner of Colorado-based Blossom & Branch Farm. “But, because of the dire straits that we’re in with climate change and carbon emissions, we really can’t afford to be taking away such a massive sequester-er of carbon.”
Bosch adds, “When [peat] is harvested, it actually releases that carbon, so then it becomes a contributor.”
With that in mind, Bosch began combing her local gardening centers for peat-free alternatives last fall. Reading the fine print on product websites and packaging was somewhat disheartening. “There’s really not a lot on the U.S. market that’s peat-free,” she says. “Part of that is because so many people don’t know to ask [for peat-free products].”
Bosch was able to find some peat-free options. She found a product called BeyondPeat at Wal-Mart, for instance. And she discovered FoxFarm’s Coco Loco potting mix, bricks of compressed coconut coir fiber and green sand.
“We just kind of grabbed a bunch of stuff off the shelves,” Bosch says. “And I said, ‘I’m going to try combining all of these things at different ratios and see if I can get a soil-blocking recipe that I’m happy with.’”
After lots of trial-and-error, she did. (She shares her peat-free, soil-blocking recipe and pointers in this video.) “We’ve had really good results with that,” she says. “But, of course, now we’re always trying to take the next step forward for sustainability. I started looking at the coconut coir, which has its own set of issues.”
Read more: Soil blocks give your plant starts a leg up.
Coconut Coir Caveat
What’s the problem with coconut coir? For starters, processing it is very water-intensive. “In its natural state, coconut coir tends to be really high in saline,” Bosch says. “Obviously, that’s not good in gardening. So, it takes a lot of water to process it to the point where we can use it.
“And water is a precious natural resource, too.”
Also, Colorado isn’t exactly teeming with coconut groves. So, the resource travels a long way to get to Bosch’s farm. As such, she began a new search for gardening ingredients with an even smaller carbon footprint.
“Every year we get more and more in depth with the sustainability piece of all this,” Bosch explains. “It’s our responsibility as growers to be cautious and mindful, because we do rely on the planet to make our living. Part of that is being responsible and taking care of [the planet] in return.”
To date, Bosch has yet to find a potting soil mix that contains neither peat moss nor coconut coir. She has experimented with rice hulls, leaf mulch and leaf mold as potential substitutes. Bosch recently changed her soil-blocking recipe again. It now includes PittMoss, a blend of recycled cellulose fiber, as a main ingredient. With the new addition, she’s been able to reduce the amount of coconut coir she uses.
“That was really intriguing, because it is material that was otherwise going to go to the landfill,” Bosch notes. “It’s OMRI-certified, so there’s nothing weird in there. It’s cellulose, and, so, its water retention is really good.
“We tweaked the [soil-blocking] recipe a little bit to make it work.”
Good, Better, Best
So far, the new concoction is working. However, finding a hyper-local resource that works just as well would be even more ideal. “Step one is to step away from peat moss and find something else,” Bosch says. “And then the next, even better step is just finding something recyclable like the PittMoss. And then the best thing is to find something that is in your own yard. Or something that you’re reusing from the [local] environment.”
Of course, accomplishing all that on a large scale doesn’t easily happen overnight. “Especially with big operations,” Bosch says. “If someone is scared to do a big transfer, say, ‘OK. Next season we’re going to try starting a quarter of our seeds in something that’s peat-free.’ Then tweak it if you need to.
“And then in the [following] year you can expand. One step at a time.”