Read more of cultivation of Aerangis macrocentra (Schltr.) Schltr.
Culture:
Light:
1500-2300 fc. Plants need filtered or diffused light and should never be exposed to direct midday sun. Strong air movement should be provided at all times. Hillerman & Holst (1986) reported that these plants need somewhat higher light levels than Aerangis citrata to flower well.
Temperatures:
Summer days average 79-80F (26-27C), and nights average 59-60F (15C), with a diurnal range of 20-21F (11-12C).
Humidity:
70-75% in summer and autumn, dropping to 60-65% for about 3 months in late winter and early spring.
Water:
Rainfall is moderate to heavy from late spring to early autumn. Averages then drop rather abruptly in midautumn at the beginning of the dry season, that lasts about 5 months until late winter or early spring. Cultivated plants should be watered heavily while actively growing, but drainage must be excellent. Water should be reduced in autumn after new growths mature.
Fertilizer:
1/4–1/2 recommended strength, applied weekly when plants are actively growing. Many growers prefer to use a balanced fertilizer throughout the 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 69-72F (21-22C), and nights average 47-48F (8-9C), with a diurnal range of 22-25F (12-14C). Rainfall in the habitat is low from autumn to early spring. Humidity remains relatively high throughout the year, however, so considerable additional moisture is available from heavy dew and late-night mist. Cultivated plants need much less water in winter, but plants should not be completely without water for long periods. Occasional early-morning mistings between infrequent light waterings should be adequate in most growing areas. Water should be increased somewhat if leaves shrivel or show signs of stress. Fertilizer should be eliminated until new growth starts and heavier watering is resumed in spring.
Growing media:
Conditions around the roots should be open and well aerated and should never be stale or soggy. As with most Aerangis species, Aerangis clavigera probably grows better and the pendent flower spikes are more easily displayed when plants are mounted on slabs of tree-fern or rough bark. Mounted plants need high humidity, however, and during hot, dry weather they may require several waterings a day. If leaves start to shrivel or wrinkle or show other signs of stress, a plant usually will recover and grow well if soaked in water for about 20 minutes at least 3 times a week. Many growers find it difficult to keep mounted plants moist enough, so plants often are grown in small hanging pots or baskets using a very coarse, open, fast draining medium to anchor the plant but allow roots to wander outside the container. Hillerman & Holst (1986) suggest that a 5 in. (12 cm) container is large enough to accommodate this orchid. 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.
Miscellaneous notes:
In the habitat, these plants bloom in autumn.
References:
This information is quoted from a Charles and Margaret Baker culture sheet, with permission from Troy Meyers
