Disa uniflora

Eugene Zielinski eez55@earthlink.net
Wed, 19 Oct 2005 19:55:20 PDT
I, too, was taken by Disa desire when I saw some pictures of D. uniflora
many years ago.  I don't grow Disas, but I did some book research to see if
I could.  I can't, at least not in the humid southeast without exceptional
cultivation measures (like an air conditioned greenhouse); I may have had a
fighting chance when I was living in central Pennsylvania.
Here are some of D. uniflora's requirements.
Water - must be pure with very low dissolved solids.  Many growers use
reverse osmosis water.  If you have one plant, you may be able to get away
with using distilled water from the supermarket.  Keep the plants dryer in
the winter than in the summer, but they should never dry out completely.
Fertilizer - very low levels, maybe none at all.
Temperature - D. uniflora tolerates low temperatures, but not below
freezing.  It is native to Table Mountain in South Africa, and it doesn't
like hot summers.
Soil - like most orchids, D. uniflora likes an open growing medium.  Long
fiber sphagnum moss has been used successfully.  Most growers repot every
Light - bright light, but not direct sun.
So...you may be able to grow D. uniflora in Santa Fe, in a greenhouse. 
Even though your summer days are warm, the nights are considerably cooler,
and Santa Fe gets plenty of sunlight year round (you can always shade the
plants in the summer.)  Disa plants are available in the USA; check the
vendors section at http://www.orchidmall.com/.  But, consider this quote from Eric
and Isobyl La Croix (African Orchids in the Wild and in Cultivation): "The
main difficulty with growing Disa species seems to be that they are very
intolerant of conditions that are not exactly as they like - too hot, too
dry, too rich, and so on - and unlike most orchids, which react to adverse
conditions by looking unhealthy, and thus usually giving time to rescue
them, Disa species react by dying without warning."
Incidentally, D. uniflora is pollinated by a butterfly, the Pride of Table
Mountain (Aeropetes tulbaghia.)  It's an important pollinator of other
plants too, including Gladiolus cardinalis, G. stefaniae, and G.
South African members: Don't hesitate to correct any mistakes I've made.

Eugene Zielinski
Augusta, GA

> Wow! For those of us who love hot colored flowers, this disa is a
must-have. Any chance that it will grow in the high, dry and cold
intermountain western US? 
> Thanks,
> - Barbara Weintraub
> Santa Fe, New Mexico
> USDA zone 5b/6a

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