The Carnivorous Plant FAQ v. 12

Q: About Sphagnum

Sphagnum
Live Sphagnum

Sphagnum
Live Sphagnum

Sphagnum
Live Sphagnum

Sphagnum products
Sphagnum products
As I just described, Sphagnum is a large wetland moss with remarkable abilities to absorb and retain water. Horticulturally, it is similar to its partially decayed form (peat moss) but it is more airy and better draining. It gets these attributes because it does not have the preponderance of fine particulates that peat has. (Such particles can interfere with water and air movement.) Sphagnum is an excellent growing medium for many carnivorous plants.

Sphagnum may be used one of three ways. First, there is live Sphagnum. If you are desperately trying to get some, have patience-if you are growing your carnivorous plants well, eventually it will pop up in one of your pots, probably originating from a tiny and unnoticed vegetative propagule. It will grow slowly but surely and within a year, it is unlikely you will ever run out of it after that. Live Sphagnum is my preferred medium for starting sundew cuttings and Venus flytrap leaf pullings.

If your growing conditions are not good enough, you will not be visited by the great god of spontaneous Sphagnum. In such a case, it is not worth your time to buy live moss, because it will die rapidly. If you want live Sphagnum, you must have a good growing environment.

Live Sphagnum is very difficult to get in large quantities. Occasionally I see it for sale, but I think these nurseries probably field collect it. If you intend to buy live Sphagnum, first determine if your suppliers have permission to collect it. When they tell you that they do, do you trust them? In your heart of hearts, do you really?

If you live near a Sphagnum bog, it is not appropriate to harvest big hunks of Sphagnum. Hell, it probably isn't even legal unless you own the land. If you must, and it is legal, take at most a few sprigs because if it will live in your collection, it will reproduce readily. Get permission from the land-owners to do even that.

The second form of Sphagnum used in horticulture is called long-fiber Sphagnum. (Carnivorous plant growing geeks sometimes call it "LFS." Fer christssakes, is it really that hard to type three words? Such growers should be poked in the eyes. ROTFL!) Long-fiber Sphagnum is just the moss, dead and dried. Long-fiber Sphagnum will often start growing again once moistened. Apparently the sterilized moss product isn't really sterilized. The horticultural properties of long-fiber Sphagnum are similar to the live stuff. Moisten this as you would peat.

Finally, there is milled Sphagnum. This is just long-fiber Sphagnum that has been broken up into the individual awl-like segments that make the Sphagnum sprigs. A top layer of milled Sphagnum, 1 cm deep, over a peat/sand mix is excellent for germinating many carnivorous plant seeds. Moisten milled Sphagnum in the same way you moisten peat.

Finding sources for long-fiber Sphagnum can be difficult. Nearly all nurseries think they have Sphagnum, but what they usually have is peat moss or the useless green moss or sheet moss materials. These products are garbage, and are certainly not Sphagnum, despite what your well-meaning nursery staff may think. Large carnivorous plant nurseries should have it (I know that California Carnivores does), so stick with them.

As I discuss elswhere, Sphagnum is not being harvested in North America or Europe in a sustainable way. This is not good. Over the last decade, I have observed the quality of horticultural Sphagnum bales decrease. More and more leaf-litter, sticks, and other crud is stuck in the bales. It seems the harvesters are really scouring their peat bogs looking for every last scrap they can get. Because the quality of local sources of Sphagnum is decreasing, people are now buying Chilean, New Zealand or Tasmanian Sphagnum. I do not know about their harvesting practices. I suspect the worst. (Although one NZ FAQ-reader says that Sphagnum is harvested in NZ sustainably.

Sarracenia purpurea
Sarracenia purpurea
I remember the depressing day when I was cleaning sticks and leaves out of my new bale of North American Sphagnum, and pulled out a dead and dried Sarracenia purpurea plant. Ever since then I have been looking for Sphagnum alternatives. In many situations, sand/peat mix in a 1:1 ratio works just as well as Sphagnum. I would like to do without the peat altogether, but have not found a good substitute yet.

If you are really interested in mosses, a good botanical reference on Sphagnum is "A Focus on Peatlands and Peat Mosses" by Crum & Planisek

Warning: when manipulating dry Sphagnum, use a face-mask and gloves, as you run the risk of contracting Sporotrichosis.

Page citations: Crum, H. & Planisek, S. 1992; Rice, B.A. 2006a; personal observation; reader contributions.

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Revised: 2018
©Barry Rice, 2018