Dave,

You need to think about Aaron's "shrink and grow" comment. I think it's a bad idea under a plant or
pad of moss.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"Dave Sheehy" wrote in message
...
Aaron Hicks ) wrote:
: These compounds (polyacrylamide and polyacrylate polymers) go by
: the generic name "superabsorbent polymers," or SAPs. They can hold several
: hundred times their own weight in water. The ones featured are probably
: the potassium polyacrylate polyacrylamide copolymer.

snip

: While they may have certain limited applications in agriculture,
: their use with orchids is minimal. These cystals expand and contract as
: they absorb or release water, so they shrink and grow. The net upshot is
: that anything that does so will eventually wash out of your bark media and
: onto your greenhouse floor (don't slip on 'em). For epiphytic species that
: require lots of air circulation, this renders them useless. Even if they
: could be retained within the media, epiphytic orchids generally die from
: too much water, rather than not enough. SAPs in this context would prove
: to be counterproductive.

snip

: I just don't see the upside to using SAPs with orchids. If anyone
: has one that can beat (pound per pound) stuff like sphagnum, I'd sure like
: to hear it.

Here's an application of this stuff that I've been considering. I grow
indoors in a window sill. A number of those are mounted orchids that
hang in the window sill. I've packed all those orchids with wads of sphagnum
in order maximize moisture retention. Even at that they still dry out
within a day or maybe two. For some types of orchids (e.g. Cirrhopetalum,
Encyclia, and Brassia) I'd like to get this up to 3 or 4 days (not sopping
wet but ideally somewhat damp). My thought is to incorporate this material
inside or underneath the sphagnum wad with the idea being that the polymer
will release its moisture and keep the sphagnum hydrated.

I do worry about how well the sphagnum will retain this stuff and how the
cyclic shrinking and growing will hold up.

Dave Sheehy