With the advent of seed-propagated Cypripedium subtropicum at a reasonable price from Hengduan Mountains Biotechnology, I have been able to try the species under several conditions and can report initial success under one set of conditions.
I attempted last year with limited beginning success. The seedlings were potted in a mix of equal parts Turface, Espoma Soil Perfector, and corse perlite, a mix used with great success for other Cypripediums by Ronald Burch. The seedlings started in my air-conditioned greenhouse with the thought that as Cypripediums, they might need cool conditions in winter, even in the subtropics. Keying on the species name subTROPICum, I moved the sprouted seedling to the warm/intermediate half of the greenhouse. It received the same quality Baltimore water as my other plants with the addition of a small amount of Osmocote fertilizer. The plant did well for two months and then collapsed.
This year, I tried again, keeping two pots in the cool section, which never exceeds 75°F and enjoys good air circulation. I have NOT given additional fertilizer, though the water contains very weak Cal-Mag through a proportioner. The other two pots were kept in the warm/intermediate section. I have found that the cool section has been a good home over many years for the Vietnamese/Chinese Paphiopedilum species (vietnamense, armeniacum, micranthum, canhii, and hangianum among others) and Cypripedium subtropicum's range straddles that border. The two pots in the cool section have grown vigorously and have maintained good color. Only one of the warm pots sprouted and it does not look happy.
There is still a while to go before I can be certain, but I hope to save others from trying the species warm. Wenqing Perner reports that Cypripedium subtropicum does not have a dormancy period.
In summary, what tentativeliy looks good is well-drained inorganic mix with very low fertility. Grow as a cool mountain plant.
I attempted last year with limited beginning success. The seedlings were potted in a mix of equal parts Turface, Espoma Soil Perfector, and corse perlite, a mix used with great success for other Cypripediums by Ronald Burch. The seedlings started in my air-conditioned greenhouse with the thought that as Cypripediums, they might need cool conditions in winter, even in the subtropics. Keying on the species name subTROPICum, I moved the sprouted seedling to the warm/intermediate half of the greenhouse. It received the same quality Baltimore water as my other plants with the addition of a small amount of Osmocote fertilizer. The plant did well for two months and then collapsed.
This year, I tried again, keeping two pots in the cool section, which never exceeds 75°F and enjoys good air circulation. I have NOT given additional fertilizer, though the water contains very weak Cal-Mag through a proportioner. The other two pots were kept in the warm/intermediate section. I have found that the cool section has been a good home over many years for the Vietnamese/Chinese Paphiopedilum species (vietnamense, armeniacum, micranthum, canhii, and hangianum among others) and Cypripedium subtropicum's range straddles that border. The two pots in the cool section have grown vigorously and have maintained good color. Only one of the warm pots sprouted and it does not look happy.
There is still a while to go before I can be certain, but I hope to save others from trying the species warm. Wenqing Perner reports that Cypripedium subtropicum does not have a dormancy period.
In summary, what tentativeliy looks good is well-drained inorganic mix with very low fertility. Grow as a cool mountain plant.
