Is Peat Moss a Sustainable Resource?

Two very different views on the ethics of using peat moss: one from garden writer Jeff Ball via Garden Rant,

Here are the simple facts. Canada has over 270 million acres of peat bogs which produce peat moss. Each year the peat moss industry harvests only 40,000 acres of peat moss mostly for horticultural use. If you do the math that comes to one of every 6,000 acres of peat moss is harvested each year. And here is the cherry on top. Peat bogs are living entities. The peat bogs grow 70% more peat moss each year than is harvested. With that data I consider peat definitely a renewable resource.

But Ball’s single source for these facts seems to be the Canadian Spaghnum Peat Moss Association. Linda Chalker-Scott, Ph.D., Extension Urban Horticulturist and Associate Professor at Washington State University in an article, “The Myth of Permanent Peatlands” (pdf), writes,

Peatlands degraded by mining activity do not revert to their former functionality; changes in hydrology and physical structure are hostile to Sphagnum re-establishment. Recently, degraded peatlands have been restored through the blockage of drainage ditches, seeding with Sphagnum, and application of a mulch layer to reduce water loss. When degraded peatlands are restored, the ability to hold water is improved but CO2 continues to be released by high levels of bacterial respiration, which represents the decomposition of mulch and other organic matter. It takes a number of years for the photosynthetic rate of new peatland plants to outpace the respiratory rate: until this happens, even restored peatlands represent a net loss of carbon to the atmosphere and thus contribute to greenhouse gas production.

Chalker-Scott goes on to list a number of peat moss alternatives including composted bark, coconut coir and paper sludge to name just a few. I use peat moss as part of a homemade seed starting mix. Reading Chalker-Scott’s article has convinced me that this is not an ethical choice.

The peat moss alternative I hear most often suggested is coconut coir. But I’ve heard an equally contradictory argument on the ethics of coir. And this study shows poor results for coir as a peat moss alternative in a seed starting mix. I tried my own comparison last summer and came up with the same results as that study. Oh, how this all gets so complicated!

So, I’m going to throw this open to you, our dear readers. I’m interested in hearing your opinions on peat moss. I’m also interested in hearing if any of you know a good peat-less, homemade seed propagation medium recipe, preferably from a reliable source. Leave some comments!

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27 Comments

  1. : I unfortunately use peat moss for square foot gardening and before that, to help break up impacted soil in my yard. A friend of mine uses it as well (though I originally heard of its eco-unfriendliness from him), because he says coconut coir products tend to have a lot of salt in them that’s difficult to remove. Although the restored peatlands output more CO2, the positive to it is that in the end it does equalize (I haven’t read the linked article yet). Shouldn’t we focus on other much more harmful CO2 emitting sources? In regards to seed propagating, my dad sticks seeds in a baggy with a wet paper towel, and when it sprouts within the week from being kept in a nice warm part of the house, teases out the seeds or tears the paper towel and just plops them into the dirt. :P

  2. Coconut coir is poisonous to dogs, and since it has to be trucked here from the tropics, it doesn’t seem to be very sustainable to me.

    There was an article in a Mother Earth News recently about how wood chips decaying makes the best soil, so maybe well-rotted wood dust would be good.

  3. Hmmm…it may seem counter-intuitive, but perhaps the best way to protect these peatlands is…to continue using peat moss.

    Especially if restoration is possible. (Even if it takes decades.)

    The worst thing, I would think, is for these lands to just sit there fallow, doing nothing, a prime target for some mining operation or construction interest to swoop in and defile it.

  4. Well, firstly, I agree that it is not a good idea to make a case for something by relying solely on studies and statistics from the industry profiting from them.

    I used coconut coir for the first time this year. I know that it isn’t a solution–the arguments against it are strong, but it seems to be the lesser of two evils to me. It’s not just about the amount of peat being harvested, but also about how it affects the ecosytem of the bog. I suppose the same could be said for coir, but at least it’s a by-product of another industry. If neither of them had these issues, I still greatly prefer the texture of the coir.

    As far as seed starting, I actually used a combination of coir, vermiculite (another iffy product) and vermicompost in a 4:2:1 ratio. I had the best results I’ve ever had. I have been also been experimenting with starting more things directly and I’m hoping to give winter sowing a go this year.
    -Megan

  5. I don’t use peat in soil mixes but I’ve been using peat pots to start seeds for years. This spring I’m switching to Cowpots or Ecopots, or the Soilcube.

  6. I second Paula’s comment. When you factor in rising transportation costs, peat becomes unfeasible for all except Canadians. My best picks are compost made from leaves and wood chips and a generous helping of worm castings.
    Has anyone tried shredded straw or finely shredded paper?

  7. I stopped using peat moss in the last century. Instead I make my own compost. Don’t forget to factor in the fuel used to transport the stuff. We have to stop our consumptive ways and learn to create our own solutions and methods. Any gardener who thinks they can’t live without peat moss is lacking in creativity. I suppose nobody gardened a century ago before the big trucks started delivering the goods we can’t live without and the big machines started ripping up the earth to make the stuff for the big trucks to drive around.

  8. It’s a tough call on both peat moss and coconut coir. I think we as gardeners and farmers need to move away from the dependence on peat moss and I don’t think coir is a better alternative despite all the green-washing.

    Some people use pure compost for starting seeds. And if you have good quality, mature compost it can work quite well.

  9. I use Jeavons’ (How to grow more vegetables) recommendation of 50:50 soil and compost. Actually I use 3 Seived soil : 3 used seed compost mix : 4 seived compost. 100% free, 100% sustainable, and works every time. I haven’t had any of the damping off problems I used to have with seed compost I used to buy. I also get excellent germination rates (pretty close to 100%).

    You do need to have a good compost making system, but I find compost making fairly straight forward if you have sufficient quantity of raw materials and a good mix of brown and green.

    The only disadvantage is that you need to dig up some soil from your vegetable beds. Jeavons seems to recommend double digging nearly every year (which if you follow his method will give you plenty of soil), but no-dig seems to be less harmful to the soil structure.

  10. Yes, I think it is possible to manage peat lands in a sustainable fashion. It is also possible to over-exploit them. Some sort of certification process for responsible use of peat might be a good thing.

    I was in Nova Scotia last summer and was hiking in an are that was logged over about 30 years ago. The regrowth included a variety of conifers and birch trees, and the floor had a thick carpet of sphagnum. It does readily regrow on it’s own accord if the disruption is not too severe. Not sure if anyone would harvest that area – might be too labor intensive compared to an open bog.

    Most of the bagged potting mixes I have seen recently contain relatively little or no peat – composted bark, wood chips and other materials are being used to create decent products.

  11. Regardless of the sustainability (or not) of peat moss or coconut coir, the packaging and transportation of all this stuff is a negative. Long before these items were available our elders were starting seeds in plain old dirt, w/compost. And that’s what I’ve used for years with no problems. Can’t stand peat pots and they don’t degrade in our dry climate. This year I’ll be trying the formed newspaper pots, having picked up one of the wooden formers at a thrift shop. Dirt works as well to start seeds as it does to grow the seedlings.

    • See, people say this all the time but it’s not really true. If you grow bog plants, good luck finding a medium that successfully replicates all the characteristics of sphagnum peat. Because no, none of my carnivorous plants will grow in dirt. They specifically evolved to get away from dirt. For that matter, my orchids also will not grow well in dirt. There are many plants that have adapted to grow in an environment created by sphagnum and where sphagnum comprises most if not all of the growing medium. Yes, that’s how nature works – if you pull a bunch of plants out of a bog and stick them in potting soil, I would fully expect dead bog plants.

      It’s not like I’m going to be planting my tomatoes in sphagnum, but before you make blanket statements like that you might want to consider there are more plants out there than just the ones you happen to grow.

  12. I can’t comment on peat moss, but coco coir is NOT sustainable. Coconut groves are grown where they cut down old growth forest and rain forest using slash-and-burn techniques. The land gets depleted, and erodes. And, as posted before, it gets shipped in from places like the Philippines which is NOT good for the environment.

  13. Its worth remembering that the concern over C02 all stems from a flawed assumption that there was less CO2 in the past, judged by the content of C02 trapped in air pockets of “ancient ice.” What was ignored by the algore crowd, is that Carbon Dioxide escapes ice under pressure… So go for it with peat moss..

  14. I garden in Texas. What works for me is Peat Humus, compost, and cedar bark mulch. I could plant in the dirt if I had a jack hammer. I’m too lazy for “difficult” soil. The humus, compost, mulch has had great water retention and I haven’t had to pull a weed in a year. I did like the suggestion of hay and will consider using that in place of the humus. The compost is my own and the cedar mulch is free from a tree trimming company.

  15. I agree with Nobody. I spend more time trying to get mother nature to not grow stuff, then to get new stuff to grow. Mother nature seems to know a thing or two about starting from seed. Dirt does seems to be a requirement.

    I have never bought peat moss. I have bought compost and soil in the past, but that was before we seriously where composting and had chickens, or to fill a garden bed.

    Cheers
    Shane

  16. What a spirited discussion! Clearly I need to do some more tests. Last year I compared different soil mixes for seed starting. I had one flat with a commercial potting mix, another with Jeavon’s compost/soil mix, and another with coir/vermiculite. This was not a fair test in that the coir/vermiculite mixture had no nutrients in it. I need to do this again with a broader range of mixes–some with peat, some with vermicompost etc. Of the three I just mentioned, the commercial mix performed the best. However, as both Jeavons and Steve Solomon point out (and those two don’t agree on much) it may be better to start seeds in the same soil they will eventually grow in. So the next question to answer is how do seedlings perform after they are transplanted. It’s also possible in our climate (Los Angeles) to direct sow most plants in the ground, with a few exceptions. Perhaps I can enlist some of you to run seed starting mix tests and report back with results. Let me know if any of you are interested and we can come up with the mixes we’ll test.

  17. Humanure! The great environmental sin of our age! We ship it out to the lake and rivers where it pollutes the very water we drink!The final great waste of the American Empire as it falls to Third World-ship before our very eyes.
    China feeds sewage to lakes, grows algae in the lakes to feed Carp, grinds the carp for fish food for fish exported to the U.S.A.! Some cities,Oslo, Norway for one, run bus services on bio-gas from sewage. Not Yankee Doodle, in his failing Empire, the silly ass poisons his lakes and streams,then imports expensive foreign oil from the OPEC and Saudi parasite nations!Goddammit!

  18. Leaf mold is supposed to be a good one, you can mix it with soil or other compost. It’s low in nutrients, which I understand is good for seed raising, as high nutrient levels can retard germination. Only drawback is the space and time (1-2 years) needed to produce it.

  19. If you get your dirt into good shape, with compost or whatever, you can start seeds in it. The only negative is that you will lose a lot of seeds to birds or whatever. So bury it.

    The main positive is that the plants will tend to be stronger than pot-grown plants. In my experience, the closer the seed or seedling is to it’s final growing place, the tougher the plant will be. The plants I’ve bought partially grown from the garden centers all end up dying, but the ones grown from seed or small seedlings thrive.

    If you want to use pots, use potting mix plus a little dirt, or a dirt+compost mix.

    Next time around, I’ll try sifting the dirt out more. Seeds want the fine soil, not the stuff with bits of wood and leaf in it. But plants want the stuff with bigger bits in it, in my experience.

  20. I have only purchased one bag of peat moss because I have been skeptical of using earth that comes from thousands of miles. If you do the math the amount of fuel burnt to move that one bag to your home is no where near the carbon given off by the mining of peat moss.

    My approach to seed starting is to grow the seed directly on the garden bed. I cover the seedling with a cover made of shade clothe. Depending on the season I add more shade clothe to block out the sun. I have not done so yet but I want to add some misters with a timer to keep the soil moist throughout the seedling period. Majority of my losses with this method is that the soil drys up to quickly (since the peat moss is used for moisture retention).

    Like some mention the best local soil comes from composted wood. I have been able to rapidly compost wood using oyster mushroom mycelium. If you do not have the time to spawn mushroom you can also get some rich soil from the soil a few inches underneath the duff of a tree. Of course don’t remove all of the trees duff cause that is another ecosystem of its own that is essential for the trees health.

  21. i second leaf mold!

    when you rake up leaves, put them into a separate compost site, or bag them up per usual, but reserve the bags, putting a few slashes into the sides. it’s helpful, but not necessary, to toss a handful or two of regular compost into the leaves. keep them damp (not wet), and turn occasionally (if in bags, just shake the bags a bit). leaf mold takes 6-12 months to mature. when it’s done, it should be loamy humus, or very close too. it has nearly no nutrients, but its properties are similar to peat moss.

    some folks pasteurize leaf mold or seed starting mix containing leaf mold in the oven for sterilization purposes. that’s up to you.

    one of my local urban gardening stores says they carry commercial “leaf compost”, but they don’t usually order it until late spring, and then it’s marketed as a mulch. i asked if they’d consider ordering some at seed-starting time (i.e. now) for those who want an alternative to peat moss in their seed starting mix.

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