What is the point of adding peat (peat-moss/sphagnum-peat/sedge-peat/etc.) to soils and substrates? What benefit does it provide?

I like the texture of it, and being that it's composed of partially decayed or decaying vegetation, I presumed that it would be full of valuable nutrients.

Although, some preliminary research suggests that it actually doesn't contain much in the way of nutrients at all; similar to other soil additives, like coconut coir, perlite, vermiculite, etc.

  • It is all completely decomposed vegetation. It is only for adding to the 'tilth' of your soil and I am assuming this is in your garden not in your pots? Peat moss used to be used for lawn seeding but they found it actually SHEDS water and the acidity is NOT good for lawns. Like Bamboo said, we humans need to STOP using peat as that resource is disappearing and destroying the peat bog environments. The ONLY additive for any soil is DECOMPOSED ORGANIC MATTER. Add it to the top of your soil and the organisms in your soil eat it, go back down into your soil and poop it out mixing it for you!
    – stormy
    Mar 12, 2017 at 16:22

2 Answers 2


Peat has been extensively used for years as a soil amendment or an ingredient in the mix for potting composts. Nutrient level is low to non existent, but because it holds onto water, it can also retain nutrients which are present in the potting mix or garden soil. It has an acid ph, and there's usually a high proportion of peat in potting mixes for acid loving plants such as Camellia or Rhododendron.

Peat, though, has taken millennia to form - it is not a renewable resource, and carbon is released into the earth's atmosphere as peat is removed from the bogs where it is found. Peat use is restricted, controlled or banned in many parts of the world for these reasons, and many gardeners avoid any product which contains peat because of these ecological principles. Primary use these days is by commercial growers, so if you are still able to buy it, use it sparingly. If you were thinking of using it as a soil amendment, composted materials are more beneficial anyway, adding humus to the soil and improving soil bio diversity, so things like composted animal manures, leaf mould, your own compost from your heap or bin are better choices. More info here: Peat Moss And Gardening – Information About Sphagnum Peat Moss.

  • I didnt know about the environmental impact of peat. Very informative!
    – y chung
    Mar 12, 2017 at 22:36

It can absorb a lot of water and release it as it is needed. But you are right, it has not much nutrients, and pure peat is also very acid.

  • The Wikipedia article mentions that it prevents roots from rotting if they're in constant contact with water, too. Is there any truth to that? I figured it must have some special property that makes people want to keep using it.
    – voices
    Mar 12, 2017 at 12:46
  • @tjt263: humidity causes rot, not water. Or better: it is combination of oxygen and water it the cause of rot. Having full water, or lack of oxygen (peat is dense, and block oxygen), reduce rot. Note: there are plenty of logs in sea and in lakes, which don't decompose for many hundreds years. Mar 13, 2017 at 8:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.