Sphagnum Moss – The Wonder Potting Media
Professional growers as well as hobbyists have long debated the best materials with which to pot their beloved orchids. For decades, the potting mediums of choice were either osmunda fiber or various bark mixes of redwood, pine, or fir. The mixes often contained additional ingredients such as perlite, charcoal, coconut husk, cork, lava rock, or just about anything a grower felt would make the mix ‘better’. Nurserymen might even consider their formulation to be proprietary.
Preparation of these special blends was no easy task. Perlite tended to float, peat moss sank, and coconut had to be triple soaked to leech the salt out. Industrial machines were often used to scramble the ingredients thoroughly.
Techniques for re-potting varied as much as the formulas. Some mixes performed best when packed tightly, sometimes using wooden rods. Others were moderately or loosely packed. Still others were just poured in. Getting consistent results for each pot was challenging.
One medium which has had a unique place in the greenhouse for over 150 years is sphagnum moss. Small seedlings, back-bulbs, and weak or sickly plants all need tender loving care. Sphagnum has anti-septic properties which help lower the incidence of rot. In addition, sphagnum offers excellent water retention so delicate roots can develop.
WHAT IS SPHAGNUM MOSS?
Sphagnum is a genus of mosses containing over 100 species and is found in bogs throughout the world. These mosses store large quantities of water – approximately 20 times their dry weight – for use during periods of drought. Bogs may be many feet deep with sphagnum on the top and decaying ‘peat’ on the bottom. Moss is a sustainable ‘crop’ as long as it is allowed to regenerate - typically 10+ years.
Like many commercial nurseries, we began our business propagating mature Cattleyas, Oncidiums, and Phalaenopsis in a bark mix and young or weak plants in sphagnum. Much to our surprise, we noticed that the meager were sometimes outperforming the strong. It wasn’t long before entire greenhouses were converted to Sphagnum Moss - the Wonder Potting Medium!
HOW TO POT IN SPHAGNUM MOSS
1. Best plants are Cattleyas, Oncidiums, Phalaenopsis, and young Paphiopedilums.
2. Soak the dry moss in water a day before. Fluff with fingers so that it is very sponge-like.
3. Choose the smallest pot that the roots will fit into. We prefer clay pots over plastic except for lady slippers.
4. Wrap the moss around the roots and push snugly into the pot.
5. Keep damp (but not wet) all the time.
6. Change the moss when it decays – usually every few years.