Paphiopedilum armeniacum

Question

I am having no success with growingPaphiopedilum armeniacum.To date, I have had three plants that died. I have had reasonably good success with its relatives, but not with this Chinese species. I grow these plants at intermediate temperatures (80º F day, 56º F nights) and pot with a bark mixture for paphiopedilums. Does Paph. armeniacum require conditions other than the ones mentioned above? -W. Krapcho

Paphiopedilum armeniacum 'Shenandoah' AM/AOS. Exhibitor, Woodstream Orchids. Photo by James Osen.

Answer

I have several suggestions based on my own experiences and observation of several baskets seen recently at Ileana de Teran's in San José , Costa Rica. Paphiopedilum armeniacum benefits from a growing medium with a pH in the slightly higher than 7.0 range; add dolomitic lime to any natural potting medium to keep it in this range. In New Zealand, I found the species responded favorably to cool winter conditions but only if it was kept on the dry side; cool and wet in the root zone was not a good environment. From June through October, it needs warm buoyant conditions and, during this time, a two- to three-week period between thorough watering is often sufficient, though of course this will depend somewhat on the conditions in your part of the country. If you water excessively in the spring, I suspect this is the main cause of the flowers aborting. I would normally grow this species in a shallow container and have cut down tall plastic pots for the purpose. However, the plants I saw growing in Costa Rica were as good as any I have seen in cultivation so, although it seems a little strange to recommend growing a terrestrial orchid in this fashion, I invite you to try a basket next time. Unfortunately, the species is once again rare in cultivation, but if you can source a plant you should soon have a basket full of stolons with flowers coming out at all sorts of strange angles. — Andy Easton