"keith" wrote in message
...
i am starting to get confused ,as a lot of growers use different methods &
give different answers!i have read in the RHS garden encylopedia(which is
like a bible for gardeners)that pine or fir bark are a excellent potting
medium with some additions to keep the mixture open & prevent it from
becoming sour.a suitable compost mix is as follows:3 parts medium grade
bark(dust free),1 part coarse grit or perlite,1 part charcoal pieces and 1
part broken dry leaves or fibrous peat substitute or peat.

As an aside, it seems to me you are looking for trouble the moment you
regard any book as being like a Bible. Doing so implies you don't ever
question it, and as a professional scientist, everything said by a mere
human being must be verified and validated, and in any scientific issue,
that means extensive experimentation. The experience others share with you
here is valuable in making inferences regarding what MAY work for you, but
to be certain YOU have to TRY the suggestions yourself.

There are several confounding issues. I don't use bark of any kind. It
isn't that I don't think it would be suitable. In my conditions, it
probably would be suitable as I do quite well with coconut husk chips. I
don't use it because it isn't available at any price in any place to which I
can easily drive. From what I have been reading lately, the principle
reason it isn't used more frequently is that a good supplier is very hard to
find.

I would use sphagnum moss, but I have not yet found a supplier of good
quality moss, and I have read that spanish moss may be even better, but I
haven't found a supplier for it. There is no point worrying about using a
particular medium if it can not easily be bought.

anyone got any comments on this mixture, as like i said it is from the RHS
book,& what they dont no isnt worth knowing!

The mixes you describe are probably fine for some species, but note, the
reference you give is for gardening, in general. That a given mix is
suitable for some species does not imply it would be good for orchids in
general or for a particular orchid genus in particular.

Now again, you're on dangerous ground. If I were still teaching at a
university, and I had a student who said such a thing to me, that student,
at a minimum, could count on being yelled at. No mere mortal, or collection
therof, can or should be treated or regarded as the fount of all knowledge.
I have worked with some of the world's best scientists, and even they are
occassionally surprised by experimental results they, or their students, or
their colleagues, have obtained. And the best of the best are ALWAYS
learning something new, which in turn implies that your claim that "anything
they don't know isn't worth knowing" is patently false!

My advice to you is first find out what media are readily available to you,
whether by mail or from local stores. Then appraise each with respect to
what you want to grow and, in particular, how you water your plants. The
reason you see different growers use and recommend different things is that
they are growing different plants in different conditions. A grower growing
phalaenopsis in Nevada will likely use different media and watering regimes
than his buddy in southern BC, and this is because Nevada is quite dry while
much of southern BC is covered in temerate rain forest. Different
environmental conditions require different cultural practices even for the
same species, and the variability increases as you consider different
growers growing different plants. This is why books like your gardening
encyclopedia provide a good starting point, but the advice provided therein
MUST be modified by the experience of your near neighbors (or people growing
in a very similar environment).

HTH

Ted