Read more of cultivation of Aerangis kotschyana (Rchb.f.) Schltr.
Culture:
Light:
2000-3500 fc. Plants grow in light to moderate shade. Plants probably flower more readily when grown with higher light, but their leaves become very yellow under these conditions. Strong air movement should be provided at all times.
Temperatures:
Summer days average 90-92F (32-33C), and nights average 64F (18C), with a diurnal range of 26-28F (15-16C).
Humidity:
65-70% most of the year, but averages increase to near 75% for a couple of months in autumn and drop to 55-60% for 3 months in late spring and early summer.
Water:
Rainfall in the region has a double wet/dry cycle with the primary wet season lasting for about 3 months in autumn and a secondary, much shorter, moderately wet season in spring and early summer. The primary dry season occurs in winter and early spring, with a shorter, moderately dry season in summer. For cultivated plants, water should be gradually increased when growth starts in spring. Plants should be watered heavily as growth becomes more active, but the medium should be allowed to become almost dry between waterings. Conditions around the roots should never be allowed to become stale or soggy. Plants should not remain dry for long periods, even during the dry seasons, because a little rain does fall each month, and additional moisture usually is available from deposits of heavy dew.
Fertilizer:
1/2-3/4 recommended strength, applied weekly when plants are actively growing. Many growers prefer to use a balanced fertilizer throughout the year. Others 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 78-80F (26-27C), and nights average 60-62F (16-17C), with a diurnal range of 16-20F (9-11C). Because of the range in habitat elevation, plants may adapt to conditions up to 6F (3C) warmer or cooler than indicated in the preceding climate table. Rainfall in the habitat is low in winter, but the little rain that does fall along with runoff from condensation provides a little moisture during the dry season. Water should be reduced for cultivated plants in winter, but they should not be allowed to dry out completely or remain without water for long periods. La Croix & La Croix (1997) report, "It needs to be kept fairly dry in winter, as the hot, high-rainfall areas where it often grows are ones where the rainfall is very seasonal, and the dry season is long." Fertilizer should be reduced or eliminated until new growth starts and heavier watering is resumed in spring.
Growing media:
As with most Aerangis species, Aerangis kotschyanai probably grows better and its pendent flower spikes and blossoms are more easily displayed when plants are mounted on slabs of rough bark. Mounted plants need high humidity and must be watered or misted at least once a day, however, and during hot, dry weather they may require several waterings a day. For those growers that find it difficult to keep mounted plants moist enough, they may also be grown in small hanging pots or baskets using a very coarse, open, fast-draining medium to anchor the plant but allowing the roots to wander outside the container. Plants should be repotted if the medium starts to break down. Repotting done just as new roots start to grow enables the plant to become reestablished in the shortest possible time. Hillerman and Holst (1986) reported that some Aerangis species seem to slowly dehydrate under normal misting or watering practices when grown on slabs. They indicated that if the leaves start to shrivel or wrinkle or show other signs of stress, the plant usually will recover and grow well if soaked in water for about 20 minutes at least 3 times a week.
Miscellaneous notes:
In Kenya, plants reportedly bloom in June and July and again in December and January, so flowering may be tied to the double wet-dry season. Long blooming and frequent blooming orchid species.
References:
This information is quoted from a Charles and Margaret Baker culture sheet, with permission from Troy Meyers
