Susan Erickson ) wrote:
: Are you sure the potting soil is not smothering the roots?

I don't believe so. I always inspect the root system when I re-pot and
there is always a healthy set of roots along with the usual contingent of
old dead roots that get pruned off. As you suggest the trick of course is
to add enough soil/vermiculite to enhance moisture retention but not so
much that you plug the whole thing up. Some of the commercially available
orchid mixes I've seen have this sort of composition. I'm just mixing my
own version. I've had one of my Catts for 15 years and it's always been
potted in my homegrown mix.

: That
: could cause the Cattleya roots to not function adequately. If
: you want your mix more water retentive add CHC or some Sphagnum
: moss, or go Semi-Hydro. You need air at the roots too and my
: guess is the potting soil is compacting just as broken down mix
: does.

Thanks for the suggestions. I saw a post recently that talked about a
water absorbant polymer (is that what CHC is?) that sounded intriguing
as a possible substitute for the soil/vermiculite. I like your idea of
mixing some sphagnum into the mix too.

Historically, I've always been most successful using bark but some of my
recent acquisitions have been potted in sphagnum and they seem to be doing
well. So, I may experiment with that media some more.

Dave