Read more of cultivation of Cynorkis purpurascens Thouars
Light:
1200-1800 fc. Plants require shady conditions and should be protected from bright light. Strong air movement should be provided at all times.
Temperatures:
Summer days average 86-88F (30-31C), and nights average 68-69F (20-21C), with a diurnal range of 17-20F (10-11C). Temperatures in the preceding climate table represent the average conditions under which these plants are found. Because of the range in habitat elevation, plants should adapt to conditions as much as 6-8F (3-4C) warmer or cooler than indicated.
Humidity:
75-80% most of the year, dropping to 65-70% for about 4 months in late winter and spring.
Water:
Rainfall is moderate to very heavy from late spring to autumn. Averages then drop rapidly into a 5-month dry season extending from late autumn to early spring. Cultivated plants should be watered heavily while actively growing, but their roots must be able to dry rapidly after watering. Water should be greatly reduced in midautumn.
Fertilizer:
1/4-1/2 recommended strength, applied weekly when plants are actively growing. Many growers use a balanced fertilizer all year, but others prefer to use a high-nitrogen fertilizer from spring to midsummer, then switch to a high-phosphate formula in late summer and autumn.
Rest period:
Winter days average 76-78F (24-26C), and nights average 56-58F (13-14C), with a diurnal range of 19-22F (11-13C). Rainfall in the habitat is low from autumn to early spring. Humidity remains high throughout the year, however, so considerable additional moisture is available from heavy dew and late-night mist. Water should be greatly reduced for cultivated plants during winter, but plants should not remain completely without water for long periods. Occasional early-morning mistings between infrequent light waterings should provide sufficient moisture in most growing areas. Fertilizer should be eliminated until new growth starts and heavier watering is resumed in spring.
Growing media:
Hawkes (1965) suggested that "These orchids are best grown in rather shallow, perfectly-drained pots or pans, filled with a porous compost of shredded osmunda, fibrous loam, gritty sand, and chopped sphagnum moss." He stated, "Most of the Cynorkis have somewhat tuberous roots, and are at least partially deciduous. Although they require quantities of water while in active growth, when the foliage starts to become yellow and wither, moisture should be virtually stopped. Care must be taken, however, that the compost never dries our completely, or the tubers may become overly desiccated. When the new shoots again appear at the surface, water should be resumed." Plants should be repotted immediately if the medium becomes stale or remains soggy after watering as these plants are very intolerant of sour conditions at the roots. With this in mind, it is probably advisable to repot every year while the plant is dormant, particularly if chopped sphagnum moss is included in the potting mix.
Notes:
Plants from humid areas reportedly have the leaf appear at the same time as the inflorescence, while those found in drier areas have the leaf appear after the inflorescence.
References:
De la Bathie, H., and H. Humbert. [1939, 1941] 1981. Flora of Madagascar 1-2. The Government of Madagascar and the National Museum of Natural History, Paris. Translated and published in 1 vol., Steven D. Beckman, 621 Palm Ave., Lodi, CA, U.S.A. 95240. Du Puy, D., P. Cribb, J. Bosser, and J. and C. Hermans. 1999. The Orchids of Madagascar. The Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, England. Hawkes, A. (1965) 1987. Encyclopaedia of cultivated orchids. Faber and Faber, London. Kew Data Base. 2008. http.//apps.kew.org/wcsp/home.do
This information is quoted from a Charles and Margaret Baker culture sheet, with permission from Troy Meyers
