We’ve just been discussing potted plants on A Spot With Pots and I thought rather than leave a very long comment I would post about it here instead. I’ve talked about this before in a post a few months ago, and other bloggers have certainly discussed this too.
Peat Moss
Almost all soil products available for purchase are based on peat moss, and this is not without controversy.
Peat covers about 3% of the earth’s surface, and to date only about 7% of this has been mined. In addition, it can be mined sustainably, but this doesn’t usually happen. You don’t have to look very hard or far to find pristine landscapes ruined by peat mining in Ireland, England, Holland, Canada and many other countries.
Peat is a huge and important natural resource, but like many other things we don’t seem to be able to reconcile commercial and environmental issues with it’s use.
The majority of peat seems to be used by industry. Finland generates 2.6% of their electricity by burning peat. Nearly all flower bulbs grown in Holland are covered with a layer of peat to protect them from winter weather. Peat is used commercially in many other ways.
Peat is also important to many indigenous communities. For example, I was in Estonia a few years ago, where I was shown what I was told was a sustainable mining operation for peat used both for heating homes in the winter and for export. I was also told that the operation was very important economically for the region.
Lack of environmental sensitivity in the industry prompts a lot of people to speak out against using it in the garden, but as gardeners what’s really the best thing for us to do?
Commercial Peat Alternatives
Quick to capitalize on the fear people have that using peat damages the environment, peat alternatives have become more available. This is the same logic that people who are afraid of sugar should drink diet Coke, or if you are afraid of getting killed in a traffic accident you should drive a safer vehicle like an SUV.
I’m not going to deny there is environmental damage from mining peat, or that you may prevent some of this damage by using a peat alternative, but I think there are few real reasons to think expensive alternatives are any better.
One of the most common peat alternatives is called coir (pronounced koy-er), a patented byproduct of the coconut industry. There’s little doubt the coconut industry generates a lot of pollution from improperly disposed of coconut shells. Will you do any favors for the environment by paying for a very small percentage of this waste to be processed into a peat alternative, then shipped from Sri Lanka where it is made all the way to your garden? Is there some reason the coconut industry can’t process and dispose of it properly locally? It’s a choice everyone has to make for themselves, but I suggest putting the matter into some perspective.
Compost is often available for purchase as a peat alternative, and is worth considering, but the quality of this is often much lower than what you make yourself. Purchased compost is often made with waste collected by local municipalities (councils), often containing a lot of contaminants. Purchased compost is usually best used for flowers instead of vegetables.
Homemade Peat Alternatives
One of the best peat alternatives is homemade compost, zero airmiles and it’s your own recycled waste.
There are three common problems with using compost. The first is many people don’t consider compost clean enough for indoor use. I don’t have any problems with it personally, but it is an issue for many people. The second problem is compost contains a lot of microorganisms, and young seedlings may be killed by these. This is called ‘damping off’. For this reason homemade compost shouldn’t be used as a seed starting mix. The third problem is it’s often not possible to make enough.
I personally use a combination of homemade compost and purchased peat. As little as 25% compost is usually sufficient to ensure there are enough nutrients in the mix, but more is better and I try to use 100% compost if I have enough available. This often results in a mixture that is too acidic for many plants, and requires the addition of some lime.
Being a Good Consumer
Regardless if you buy peat or peat alternatives, remember you are buying a natural resource that shouldn’t be wasted. Like any other agricultural product, try to buy locally and as direct from the producer as possible. If you are buying it from the garden center, you probably won’t have any choice in this. Above all consider alternatives you may already have, like normal dirt or homemade compost. Also try to reuse or recycle potting soil when possible.
Always keep in mind there is more profit for any store if you buy a processed product, and this is what they will always try to sell you. Peat based potting soil is a perfect example of this. There are not enough nutrients for plants in plain peat moss, but by taking plain peat moss and adding a few cents of chemical fertilizer and a fancy label with a brand name, it can be sold at a huge markup. This is exactly what nearly all commercial potting soil is. Some have sand, compost or other things added, but by reading the list of ingredients on the label you can almost always buy the individual ingredients and make it yourself for much less money. If you are an organic gardener make sure any commercial potting soil you buy is clearly labeled organic! Making it yourself is the best way to make sure it only has what you want in it.
I often have the problem here in Amsterdam that I can’t buy plain peat moss in the right season. Garden centers know they are competing with people making their own mixes with homemade compost, so they just don’t sell plain peat moss in the spring and summer. Since it is used by gardeners growing flower bulbs, it’s often available in the fall, so I usually have to buy it out of season and store it.
Peat moss is an important natural resource for gardeners, but it’s cheap and unpatented, putting a lot of pressure on retail outlets to wean us off and onto more expensive and patented alternatives like potting soil mixes and peat alternatives. For this reason, the day may come where plain peat moss is simply no longer available for purchase.
Another thing to consider when buying so-called organic potting soil is corporate “greenwashing”. I bought a bag of potting soil from Scott’s earlier in the season and while it may have been organic material, it seemed to be mostly uncomposted bark chips and other fillers. I was planning on using it for a seed starting mix, but it wouldn’t hold moisture and I ended up tossing it into the compost pile.
Hi Steven, While you were leaving this comment, I was just adding a link to a post Rebsie made where she mentioned the same thing. I think there’s a lot of dishonesty in the world of potting soil.
Yet another informative post. Man, I am learning so much from you lately! Wonderful!
My family comes from Holland/Netherlands…where peat moss is probably still an industry (long line of Gasselte schippers, a fascinating history). Removing it has an impact on the environment (land level,water table, unique habitats, non-renewable, slow regeneration in that order or priority). It can be a bit of a hazard itself (flammable).
I don’t use peat moss. Coir seems to be more readily available here. I don’t use it either, but was unaware of the environmental impacts and political and economical factors.
Making your own seems to be the way to go.
One thing though to remember when trying to protect the peat bogs is that they are often the modern result of medieval tree clearing, so even though a ecosystem has developed around them in the modern world. They are often a sign of a very disrupted local environment, where once trees and understory plants once thrived
I was told that one major ingredient in potting mix is the dregs from Coffee from big companies like bushels and nescafe?
P.S Your blog is a great resource and this is fantastic information.
Great post Patrick. It so often happens that when we think we are being “green” we’re often causing more problems than we’re solving. Recycling is a case in point – what with transport to the plant, and the energy used by the recycling process itself, recycling can often have an ultimately negative effect on the environment. Which doesn’t mean it’s not sometimes a viable option. But it’s not an easy way out – cutting down on use, and reusing what we have to use is still going to have a far more important effect than recycling.
hello . If you have office in netherland for export the peat moss . Reply me
Hi Majdi,
I’m sorry, we don’t sell peat moss here. I don’t know of anyone else who could help you either. Thanks for stopping by.
is it not possible to sterilise compost to be a seedling growing medium by putting it in the oven for a while??
Hi Catrin,
Thanks for leaving a comment, and sorry it took so long to get back to you! I’ve been out of town for a few days.
Yes, this is something we discussed on later posts and in the associated comments. Yes, it can be sterilized by putting it in a medium oven for about a half hour. It does smell bad, and if you need to sterilize a lot it can take quite a lot of energy. Someone also suggested sterilizing it with household bleach, which in theory should also work.