Calanthe Saint Aubin
Calanthe Saint Aubin is a complex hybrid Orchid bred from three separate deciduous species of the terrestrial Calanthe, C. vestita, C. regrieri and C. wilhamsii. From the very odd-looking, 7cm (3in) pseudo-bulbs arise graceful, stunning sprays of bloom. Leaf growth appears and then drops well before flowering, which occurs in late Winter through to Spring.
When in growth, provide warm conditions of 18-20°C (65-70°F) during the day, and a night minimum of 13°C (56°F). If temperatures exceed 20°C (70°F), provide draught-free ventilation. During the rest period, keep at around 13°C (56°F). Once new growth is seen, gradually increase the growing temperature.
Grow these plants in bright, but indirect, light: provide supplementary lighting in Winter.
Keep C. Saint Aubin well moistened throughout the growing season, and water again once the surface of thehas begun to dry. After flowering, and when the leaves yellow, cease watering and turn the pot on its side to dry. When new growth appears, resume watering. The first water given after the rest period may run straight through: place the pot up to 2cm (1in) below the pot rim in a bowl of water, leave until the compost is thoroughly moistened, then allow it to drain through. If the plant refuses to cease growth, continue watering.
In the growing period, Calanthe need a high degree of humidity, but misting should be avoided. Stand the pot on a tray of moisture-retentive pellets. In tile-floored plant rooms, a daily damping down in hot weather can be beneficial.
Feed plants in active growth with a half-strength plant food every week; do not feed resting plants.
Grow in a proprietary Orchid compost. Repot the pseudobulbs when new growth is visible, usually around April, placing 3-4 in each pot; keep a minimum of four pseudobulbs on the parent plant.
As the flower stems are so long, insert a suitable cane when repotting: this will avoid root disturbance later.
Aphids cluster on the succulent shoot tips and should be controlled with a suitable insecticide.
Scale and Mealy Bug should be eradicated with methylated spirit and a cotton bud.
Red Spider Mite is indicated by the characteristic webbing. Misting the leaf undersides can deter these pests during the growing period, but there is no truly effective insecticide available on the domestic market; discard infested plants.