Read more of cultivation of Aerangis thomsonii (Rolfe) Schltr.
Culture:
Light:
1000-1800 fc. Conditions should be shaded with filtered, diffused light, and plants should not be exposed to direct midday sun. Strong air movement should be provided at all times.
Temperatures:
Summer days average 67-72F (19-22C), and nights average 47-48F (8-9C), with a diurnal range of 19-24F (11-13C). Plants should thrive if grown in the cool, moist airflow from an evaporative cooler. These are the average conditions under which these plants should be grown. Because of the range in habitat elevation, they should adapt to conditions 6-8F (3-4C) warmer or cooler than indicated in the preceding climate table. Growers report that plants will grow in intermediate conditions if given a shaded but airy place, but cool temperatures are preferable. If grown under intermediate conditions, however, it is important that plants be able to cool down at night.
Humidity:
55-65% for about 2 months in late winter and early spring and again for 2-3 months in summer. Averages increase to 70-75% for the remainder of the year. Averages in the habitat may be somewhat greater than indicated in the preceding climate table, however.
Water:
There are two wet/dry cycles during the year, with a dry season in winter and early spring followed by a fairly short, 2- to 3-month wet season in late spring and early summer. This is followed by a rather short somewhat drier season in summer and then by a 3-month wet season in autumn. Cultivated plant should be watered heavily while actively growing, but they must be able to dry rather quickly after watering.
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 use a high-nitrogen fertilizer from spring to midsummer, then switch to one high in phosphates in late summer and autumn.
Rest period:
Winter days average 62-63F (17C), and nights average 44-46F (7-8C), with a diurnal range of 17-18F (9-10C). Growers are reminded that these plants should adapt to conditions 6-8F (3-4C) warmer or cooler than indicated in the preceding climate table. Water should be reduced for cultivated plants during the winter dry season, but plants should not be allowed to remain completely without water for long periods. Occasional early morning mistings between infrequent light waterings should provide sufficient moisture in most growing areas. Water should be reduced for plants during the secondary dry season in summer, but plants should not be allowed to become as dry as during the more severe winter dry period. Fertilizer should be reduced or eliminated when water is reduced.
Growing media:
As with most Aerangis species, these plants probably grow 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, 3-5 in. (8-13 cm) hanging pots or baskets using a very coarse, open, fast draining medium to anchor the plant but allow 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.
References:
This information is quoted from a Charles and Margaret Baker culture sheet, with permission from Troy Meyers
