Peat Moss vs. Sphagnum Moss and more

The mailbox of Ask Gardenerd has been receiving some great questions this week.  Here’s another about the difference between moss and moss:

“A question about moss… What is the difference between
peat moss, sphagnum moss, and the green moss that grows around the
ground?  Going into the 3rd year with my raised bed, and it has many
patches of green moss. Is this detrimental to the plants?   Should it be
removed or turned back under into the soil?  Thanks in advance.  Judy”

I love this question, thanks for writing in.  There is a difference in the functionality of these different mosses, and it’s good to know which is which, so you can use them properly.

Mossytrees1
Mossy trees in Mexico’s National Park in Uruapan

Peat Moss – Technically called Sphagnum Peat Moss.  This is the stuff you see most often in bags at the nursery, sold as a soil amendment.  It is comprised of decaying material harvested from bogs.  It is the dead material underneath the living part of the plant (we’ll talk about that in a second).

These bogs take between one to three thousand years for nature to make them, and we harvest the contents much faster than that.   The world is experiencing a dramatic loss of peat bogs, between 89-98% of the bogs that once existed are now gone.  That’s why I recommend using coir, the outside hull of coconuts (which is a waste product)  instead.

Sphagnum Moss –  This is also found at nurseries or craft and hardware stores, and is used to line hanging baskets.  It’s often used to cover the soil in decorative topiaries.  This is the living part of the plant that dwells above ground.  It covers the bog and without it the bog can not thrive.  This part is usually removed in order to access the peat below, though many countries have adopted sustainable harvesting methods to preserve the sphagnum layer while still accessing the decaying peat below.

Sphagnum moss can contain some pretty nasty fungal spores, which if not handled properly (or sterilized before being sold) can get under your nails and cause major health issues.  It is recommended to use gloves when handling decorative sphagnum moss.

That other moss – Green moss or algae (and it could be either) that appears on the soil surface usually crops up in places where soil has poor drainage and more shade.  In reading about the possibilities, I came across this helpful guide from University of Georgia:

Controlling Moss and Algae in Turf

To summarize this and other sources of info,  here are a few tips:

It’s generally harmless – you can scratch the soil surface to disperse it, and it will most likely come back, but it won’t harm or kill your plants.

Check soil pH and fertility – algae tends to grow in infertile areas where there is light, so check your soil and amend with organic fertilizer as needed.  Add lime if the soil is too acidic (another happy breeding ground for algae).

Add compost – to improve drainage, or create raised beds.

Cut back on watering – the presence of algae or moss is a sure sign that the soil is too wet.  Let the soil dry out between waterings if possible and see if that doesn’t improve things.

Thanks for writing in.  I hope this helps.

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8 Responses to Peat Moss vs. Sphagnum Moss and more

  1. Jon Williams says:

    In Canada, it has been estimated that new peat bog mass accumulates 60 times faster than the amount harvested each year. Approximately .02 percent of the 270 million acres (422,000 square miles) of Canadian peat bog are used for peat moss mining.[

  2. John Ammer says:

    Hi,
    I bought a big cube of sphagnum moss which is labeled from Independence, OR.
    I am planning to break this up and add to the soil in my very small vegetable garden.
    IS THIS a bad plan? Maybe I have made a mistake buying this moss?

    • Christy says:

      Hi John,

      Look for the word “peat” because that’s what you want to add to your garden. Sphagnum moss is generally used in crafting and as a top layer over potted plants or hanging baskets. Peat moss is what is used to amend garden soils. If you add sphagnum moss to your garden it probably won’t cause any damage, but it may not have the effect you’re hoping for. In the future, we recommend using coconut coir instead of peat moss. It’s a waste product instead of a not-quite-renewable resource. Keep us posted on how thing go.

  3. Brendan says:

    Its a bit confusing to be honest.
    my plants at home consist of yukkas, 2 majestic palms, 1 bird of paradise.and 2 cordylines.
    Inside i have a small birds nest tree fern.
    All i have used is peat miss mixed with potting mix for the birds nest fern.
    As for outside…..no peat moss or sphagnum moss.
    All plants have been repotted and fertlised as its the start of summer here in australia.
    I am considering putting a layer of sphagnum moss on top of my small palms to keep the moisture in the soil underneath.

    My question is……can i use a mixture of premium potting mix with peat moss AND also have a layer of sphagnum on the top (about 2 inches) ?
    Or you can only use 1 or the other ?
    Beneficial using both as palms like a good drink amd the peat will be excellent for that.
    Or the sphagnum top layer will also keep the moisture in so it doesnt need watering everyday during summer.

    Any ideas anyone ?
    I can try and post pictures of what i have.

    • Christy says:

      I wish I could help you Brendan, but I don’t use peat moss because of its environmental impact) and I’m not a pro on palm trees. I would much prefer to mulch with leaf litter or chip bark, both of which are waste products and nature made them to shed naturally. Perhaps someone here can post a suggestion specifically about peat.

  4. Susan Fries says:

    I have purchased two staghorn ferns and it is recommended to plant them in sphagnum moss. I have checked my local garden centers and they only have the sphagnum peat moss. Would this product do as well?

    • Christy says:

      No. Sphagnum moss and sphagnum peat moss are not the same thing (which you clearly already know :-)). Sphagnum moss is the living part of the peat bog, and it’s a product that you won’t find at most nurseries, unless they sell orchids or other decorative houseplants. Sphagnum peat moss is the dead material underneath the living part of the peat bog. That’s the stuff you’ll find at nurseries and in just about every potting soil mix on the market.

      You’ll find sphagnum moss at craft stores, since it’s used most often as a decorative cover for the tops of potted plants, or as a liner for hanging baskets. It holds in soil and moisture, and in the case of your staghorn ferns, which are epiphytes (meaning they grow without soil, roots exposed to the air), it will keep the root area moist while still allowing air flow.

      So check your local craft store or flower shop for sphagnum moss instead.

  5. Angela Reid says:

    A big thank you. This answers my question perfectly, as well.

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