Having a good source of a good orchid medium is essential for success in growing orchids. Many of us use a type of bark for our orchids, which makes sense, since most of them are epiphytes (growing on trees).
Whichever type you choose to use, it is important to make sure you store the bark in a dark dry area.
If the bags are wet, cut them open and allow it to dry, and then re-bag if necessary.
If stored wet, snow mold (Ptychogaster sp.) may contaminate the bag. So avoid purchasing wet bags. Look for white spots on the bark, or in more obvious cases, very fine hair like roots. If the bark has snow mold, do not use it!
I have been battling this for years (with several organic medias), and the results have been devastating. This fungus has roots or mycelia that are saprophytic (feeding on dead plant material or the bark), but can envelop the bark and the whole orchid root system of the orchid, essentially smothering it.
Cattleyas especially will not tolerate snow mold. The roots just die as well as the growth eyes on the rhizomes turn black. Applying fungicides provide little help, so it is best solution is to repot the orchid into fresh media.
I have recently changed to Radiata (Kiwi) Pine Bark from New Zealand, making sure it is stored dry, and so far so good.
I mix six parts of bark, with three parts of #3 perlite, and one part of Pro Mix Peat Moss. I moisten and mix the peat/perlite, then incorporate it to the bark.
This ensures that the peat sticks and is incorporated evenly throughout the mix. This moistened mix can be stored for short periods of time. This is my basic mix, but it should be modified to suit each person’s specific growing conditions.
If this does not work, I’m going back to Blue Rock.
The Windward Orchid Society meets at 7:30 p.m. on the first Wednesday of every month at the King Intermediate School Cafeteria, located at 46-155 Kamehameha Hwy. in Kaneohe.
Become a member
Join the Windward Orchid Society to help promote, educate and show an appreciation of one of the most beautiful and exotic of all plants. The Orchid.