In some testing I did years ago I found vermiculite to be a very bad media component for Orchids. It holds too much water and because it is expanded mica, it has a tendency to collapse over time. Once collapsed it fill the air spaces in the media making it a water holding mud. Perlite is a much better supplement as it holds its shape over time and helps provide expanded air space in a media.
I find sphagnum to be a very good media for a variety of orchids. You do have to repot with it on a yearly basis. I have never grown Maxillaria, but it works great for Pluerothallids, Paphiopedilums, Phalaenopsis, Cattleya's and Oncidiums. It is also a great media for seedlings as you are moving them on to larger containers most of the moss falls away from the roots and I can repot into what ever media I am moving the seedlings into. What media is not getting expensive and difficult to find quality material in quantity. I never look down at any media as all of them have their place with some orchids. It depends on your growing conditions and your cultural conditions. One growers tea is another growers poison. At 1:40 PM +1100 11/18/05, [EMAIL PROTECTED] wrote: >I am trying to avoid the use of sphagnum moss for several reasons: >1. it deteriorates over time and can then destroy roots of orchids >2. when used alone, it is difficult to remove, especially from fine >roots as in maxillaria >3. sphagnum moss is getting expensive, and harder to find a source >of good quality moss. > >My recent solution to this problem has been the use of seedling >grade bark, 5mm, along with 25% 5mm perlite. It has been very >satisfactory for most genera requiring a damp substrate. >Has Vermiculite been useful, either alone or with/as an additive? In >what circumstances and purpose please? >Paul > >_______________________________________________ >the OrchidGuide Digest (OGD) >[email protected] >http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com -- --Tom /---------------------------------------------------------------------------------------- | Tom Hillson Agriculture Computer Services Manager |(515) 294-1543 College of Agriculture | Iowa State University ----------------------------------------------------------------------------------------- |"The only thing I have too much of is too little time" _______________________________________________ the OrchidGuide Digest (OGD) [email protected] http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
