Wild Sphagnum cf. cristatum growing wild in the Brindabella Ranges above Canberra. Most Sphagnum species are cool-growing species from temperate climates (note the snow!), although I have seen a species (probably Sphagnum perichaetiale) growing in Wallum heathland in southern Queensland.
Why use Sphagnum moss?
Sphagnum moss makes a great CP growing medium, but it is not the only option for great plants. The main benefit it offers is providing an acid and very pH stable soil for CPs, which typically grow in very acid (and therefore nutrient poor) conditions. The reason for the stable pH is that live Sphagnum continually pumps acids (hydrogen ions) into the environment. These acids react with soil nutrients and prevent large plants (tree species) from outcompeting the Sphagnum and overgrowing its environment (light being the limiting factor). Because of its acid production, Sphagnum is an ideal media for CPs.
Read this before you think about using Sphagnum for your CPs...
Because live Sphagnum is no longer readily available in Australia from legal sources, it should only be used with great care and restraint. Only use it if you intend to keep it alive and are prepared to provide ideal conditions as suggested here and by other resources. You should never use it as "just a growing media". Unless you are growing plants that absolutely need Sphagnum (like Darlingtonia and some epiphytic Nepenthes, and even these can be grown in other media, albeit not as well), use a Sphagnum peat or other appropriate mix to form the bulk of the media and only ever use Sphagnum as a living organism to cover the surface of the pot in order to create a stable growing environment and for aesthetics. You should also aim to cultivate Sphagnum for its own sake and self sufficiency, as well as conserve Sphagnum during repotting.
About Sphagnum in Australia
More wild Sphagnum growing in the Brindabella Ranges. Note the Utricularia dichotoma flower at top right of this image.
The genus Sphagnum contains 250 named species with just 6 growing in Australia. Most of them occur in temperate regions, although one species growing here is a subtropical or tropical specialist that occurs in Queensland and the Northern Territory as well as in tropical Asia. All Sphagnum are niche specialists and most create their own ecosystems (ie. Sphagnum heathlands). These environments form a tiny fraction of Australia's biological diversity and are very sensitive to environmental change (including climate change for alpine and sub-alpine specialists). Sphagnum is protected in all states and territories of Australia, meaning you cannot just go an dig some up. As licenses in Tasmania (the only state that permitted harvesting) have reportedly been cancelled, the only mosses now available are those already in cultivation by CP and orchid growers.
The six named species are:
· Sphagnum cristatum (subalpine NSW, ACT, TAS & New Zealand); robust, tussock forming species, green or occasionally light tan to light purple. Almost certainly the dominant species in cultivation.
· Sphagnum perichaetiale ( N.T., QLD and N.S.W. Also in New Zealand (North Island), India, SE Asia, Malesia (as opposed to Malaysia!), Melanesia, Fiji, South America, the Caribbean, eastern U.S.A., southern Africa, Madagascar and Mauritius); tropical/subtropical species, associated with flowing water over rock or acidic substrates in shaded areas. Probably not cultivated.
· Sphagnum australe (lowland to subalpine N.S.W., A.C.T., VIC. and TAS., also in South America, southern Africa and New Zealand); prefers relatively well drained sites. Leaves pendant, whitish green. Possibly in cultivation.
· Sphagnum falcatulum (NSW, VIC & TAS; ?QLD), very fine foliage, in wet to submerged conditions. Sea level to subalpine altitudinal range. Probably not cultivated.
· Sphagnum fuscovinosum (Tasmanian endemic); red foliage, grows submerged, subalpine and true alpine conditions.
· Sphagnum novozelandicum (WA, NSW, ACT, VIC & TAS; also NZ); yellow-brown to brown-purple, sea level to subalpine, cushion forming species. In wet conditions in shrubland, grassland and even roadside ditches. Possibly cultivated.
The most commonly encountered species as far as Australian CP growing is concerned is probably Sphagnum cristatum, which is one of the most widespread Australian species. This moss is a green type, with plants growing in strong sun occasionally becoming purplish at the growing point. Sphagnum novozelandicum is probably also in cultivation (possibly mixed with S. cristatum), and I suspect some NSW growers have Sphagnum australe as well.
Only one Australian species (Sphagnum fusconivosum) is strongly reddish in colour. Follow this link to see a photo of this species on Flickr. As you will see, it is almost entirely aquatic and a rather bushy plant that lacks a strong stem. It appears to rely on water's buoyancy to hold it erect, much like water plants like Elodea or milfoil. Given this unique habit, it is probably not suitable for CP cultivation. We do not have the terrestrial red Sphagnum that the United States has (or if we do, it is as yet unnamed and unknown to Australian moss taxonomists). Do not even think about importing live Sphagnum, as it will be illegal under our Quarantine laws. In addition, it is a major pathogen risk, and not just from a plant pathology perspective. Sphagnum can cause human health issues (see Barry Rice's page on sporotrichosis).
The major taxonomic work on Sphagnum in Australia is by Rodney Seppelt. You can access this work by clicking on this link (ANBG site).
Plants cultivated in Australia by CP growers
As noted above, most Sphagnum in cultivation appears to be either Sphagnum cristatum or S. novozealandicum, but some NSW CP growers have a much finer, more slender looking species with hanging foliage that may be S. australe. No-one seems to have bothered keying out their mosses (see the Seppelt work above for a taxonomic key - you will need a microscope)!
This Sphagnum was (hopefully) obtained as live moss harvested from Tasmania under state-issued collection permits, or before permits were required. Sphagnum moss was also harvested from the Brindabella Ranges above Canberra, but stopped many decades ago. It is unlikely any of that moss remains in cultivation.
My experiences with growing Sphagnum Moss
I obtained my live Sphagnum moss either via Bunnings (as Brunnings or Amgrow brands) or via members of the AUSCPS in Sydney who brought direct from a licensed harvesting operation in Tasmania. My first success in growing it was as a substrate for Sarracenia under windowsill cultivation, but I have also grown it well in greenhouses and terrariums with Sarracenia and Nepenthes/Drosera/Pinguicula, respectively.
Sphagnum is most efficiently used as a top dressing in pots of standard CP mixes. To grow it, use live strands that are buried 5 cm or more deep into your CP mix (use of pure Sphagnum must now be considered wasteful) to ensure it stays wet enough to grow. It does not do as well if it is simply placed on the top of peat moss, as it is vulnerable to drying out. Bury each strand so the growing point protrudes from the soil and preferably remains in contact with the soil surface; try using chopsticks or a pair of forceps to do this efficiently. The moss then grows from the exposed end.
Sphagnum does well under the shaded canopy of taller plants like Sarracenia or Nepenthes, especially if humidity is kept high. Full sun is very detrimental to its growth, as are hot, drying winds. Water must be maintained at high levels during summer, as it looses water both via transpiration and also from honeybees that drink moisture directly from the live moss. I always find numerous bees doing this in mid summer; they can learn how to get into greenhouses through even a small gap.
If you want to grow Sphagnum as a top dressing, you should also consider using trays that extend 10 cm or more above the height of the pot used. Solid-bottom broccoli boxes are good in this regard, because they can be cut to custom heights for your setup. Be sure to drill drainage holes at the desired height to allow the tray to drain adequately and not submerge the pots). Once the moss becomes 5-10 cm long (2-3 seasons needed), it can be harvested and used on other pots.
In terraria and climate controlled greenhouses, Sphagnum can grow much faster than under either unregulated greenhouses or outdoor conditions. In terraria, it can quickly become etiolated (stringy) as the newer growth climbs over older growth. However, terraria are a good way to quickly produce a reasonable volume of moss quickly (the etiolated moss soon clumps up if acclimatised to less humid conditions). I use a Cool White 24 or 48 watt compact fluorescent with the highest Kelvin temperature available; the Phillips Tornado series has worked well for me previously. My setup used small lengths of PVC pipe (2 inch lengths) and some acrylic light grating (ask a pet store that specialises in reptiles) to create a platform that I covered with coir basket. I filled the terrarium with water to the platform depth and placed a small aquarium heater underneath to maintain a temperature in the mid 20*C-30*C range. Sphagnum was then placed over the top of the platform to a depth of about 1 inch and allowed to grow. Using this method, I produced enough moss in 6 months to top dress many Sarracenia pots.
If terrarium cultivation is not practical, try growing it in drained broccoli boxes (sterilised with bleach and well washed first!). Use an undrained nursery tray underneath. I'd suggest planting strands of live Sphagnum moss into peat. Grow it in a shaded location that is cool. Make sure you keep the soil very moist to wet. If sun and desiccation is a problem in your conditions, try covering it with a light coloured shade cloth (ca. 70%). The ACT government used this method with good success to rehabilitate Sphagnum heath at Mt Ginnini that was burned after the 2003 bushfires (this heath is a RAMSAR listed wetland and the last major habitat of the northern corroboree frogs).
If you are lucky enough to have a climate controlled greenhouse for Nepenthes that is kept humid via misting, Sphagnum should be no problem to grow, and you should aim to progressively increase the amount you grow and make some available for other growers.
Weblinks
The Australian National Botanic Gardens (ANBG) have a webpage for cultivating Sphagnum moss, which you can view here (although you do not need the stringent conditions that link specifies, as described above). Bluegrass Carnivores also have a good website with some alternative methods for Sphagnum growing, which you can view here. Some of these may or may not be appropriate for our drier climate. But note the 12 cm water table depth that the latter resource recommends.
