Read more of Cultivation of Angraecum arachnites Schltr.
Culture:
Light:
1200-2300 fc. Light should be filtered or diffused, and plants should not be exposed to direct midday sun. Strong air movement should be provided at all times. Hillerman & Holst (1986) reported that this orchid should have fairly shaded light levels.
Temperatures:
Summer days average 78-80F (26-27C), and nights average 60-61F (16C), with a diurnal range of 17-20F (10-11C).
Humidity:
75-80% most of the year, dropping to near 65% for a short time in spring.
Water:
Rainfall is very heavy from late spring to early autumn. Amounts then decrease fairly rapidly at the beginning of the 5-month dry season, which lasts from late autumn to early spring. Cultivated plants should be watered heavily while actively growing. Water should be reduced after new growth is completed in autumn.
Fertilizer:
1/4-1/2 recommended strength, applied weekly when plants are actively growing. Many growers use a balanced fertilizer all year. Others, however, prefer to use a high-nitrogen fertilizer from spring to midsummer and then switch to a high-phosphate formula in late summer and autumn.
Rest period:
Winter days average 68-70F (20-21C), and nights average 48-50F (9-10C), with a diurnal range of 19-22F (11-12C). Rainfall in the habitat is low in winter, but additional moisture usually is available from heavy dew and mist. Cultivated plants need less water in winter, but they should not dry out completely or stay dry for long periods. Fairly regular early-morning mistings between infrequently light waterings should provide sufficient moisture in most growing areas. Fertilizer should be reduced or eliminated until new growth starts and heavier watering is resumed in spring.
Growing media:
Plants are usually grown in well-drained pots or baskets tightly packed in a very open, fast draining medium such as a mix based on fir bark or shredded tree-fern fiber or chunks of tree-fern fiber or osmunda. Hawkes (1965) reported, "The various bark preparations have not proved to be acceptable for use with Angraecums, or other angraecoid orchids." Hillerman and Holst (1986), however, stated, "This little plant can be potted in fine fir mix or tree fern fiber, but it grows equally well mounted if not allowed to become dehydrated." Materials such as perlite or chopped sphagnum moss that help hold the medium open and also retain some moisture are often added to the potting mix. In addition, charcoal is often added to help hold the medium open and keep it from becoming sour. A plant can be set back for a long time if roots are damaged during repotting. One way to avoid root damage is to place the plant, still in its original pot and place everything in a larger pot adding fresh coarse potting mix around the outside of the smaller pot. Repotting up is not advisable if the original medium has broken down so that it stays soggy. When plants reach blooming size, the roots should be disturbed as infrequently as possible, as they may sulk for 2-4 years after being disturbed. Therefore, it is preferable to select a coarse potting medium that breaks down very slowly, which makes shredded tree-fern fiber preferable to fir bark. However, plants cannot tolerant stale conditions around the roots, so plants should be repotted immediately if the medium starts to break down. If the medium is still good, repotting may be done whenever the plant outgrows its container. Repotting is best done just as new roots start to grow, which allows 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
