Live Welsh Sphagnum Moss For Inverts

The water-holding in sphagnum is done by cells that are already dead. Every leaf is a mesh of small green living cells wrapped around much larger empty ones, called hyaline cells, which are perforated to the outside and do nothing but fill. That structure is why a handful of bog moss holds something in the order of sixteen to twenty-six times its own dry weight in water, and why it goes on releasing it slowly instead of all at once. There are around 380 species worldwide and thirty-odd recorded in Britain.

The same chemistry that makes it useful in an enclosure made it useful in a field hospital. Sphagnum acidifies its surroundings by taking up calcium and magnesium and releasing hydrogen ions in exchange, and compounds in its cell walls slow decomposition down. Dressings made from cleaned sphagnum were gathered across Britain, Canada and the United States during the First World War, on the strength of a case made by an Edinburgh surgeon and a botanist in 1914, and the moss went into wounds because it absorbed heavily and resisted spoiling. In a tub it does the smaller version of the same job.

This is living moss, picked by hand in Wales, not the dried compressed kind. It arrives springy and damp. Use it for humidity pockets and moist hides, as a laying medium, in springtail cultures, as cover for tarantulas and scorpions, and anywhere you want a corner to stay wetter than the rest without soaking the substrate.

Treat it before it goes in

Moss picked outdoors comes with residents. Mites are the usual passengers, and there can be plenty of them. Rinsing under cool dechlorinated water while teasing the strands apart, then holding it in a clear sealed tub for a week or two and picking off whatever surfaces, will keep the moss alive and deals with most of it. If you need certainty rather than most, kill it. A domestic freezer runs at about -18°C and the tissue-lethal threshold for sphagnum sits near -16°C, so two or three days in there will almost certainly finish the plant along with the passengers. Heat is the same story from the other direction: half of it dies at around 50°C, so boiling water over it, or a damp minute in the microwave taken in short bursts and not in one go, sterilises thoroughly and leaves you with material that is still perfectly good for moisture and cover. For an isolated culture or anything delicate, take the certainty. For an established bioactive setup, a rinse and a quarantine is usually enough.

Keep what you do not use in a loosely closed bag in the fridge, where it will stay in condition far longer than it will on a shelf. If you want moss purely for water retention and have no interest in keeping it alive, the dried sphagnum is less work and stores indefinitely. For culture setup, our article on long-term springtail cultures covers where moss helps and where it does not.