Vanda and Ascocenda Culture

Vanda and Ascocenda Culture
Vandaceous plants have a monopodial growth habit. They are strap-leafed plants having flat, leathery
leaves.
TEMPERATURE: Vandaceous orchids grow best under warm daytime conditions of 65°F or higher,
but can withstand long spells of hot weather and short spells of cold. They will continue in active growth
anytime of the year if given warm temperatures and bright light. Night temperatures generally should be
60°F or higher but not lower than 55°F.
HUMIDITY AND VENTILATION: Vigorous air movement from a fan is important to keep leaf
temperature down in a greenhouse under the summer sun. It is important to restrict air movement under
colder temperatures. On hot, sunny days, at least 60% humidity is appropriate.
LIGHT: The ascocenda orchid can take full morning sun but needs shade during the hottest part of the
day and during most of the day in the summer. Under greenhouse conditions with high humidity, the
amount of sunlight should be only enough to keep the temperature within the appropriate range.
WATERING AND FEEDING: High daytime humidity is essential, especially on sunny days.
Vandaceous plants kept outdoors may need watering and misting several times daily during the growing
season when the sun is bright. Indoors, somewhat less watering is required, but misting once or twice a
day in hot weather will be helpful. Water sparingly in winter, during long cloudy spells, or after
repotting. Vandeceous orchids are heavy feeders. Plants in greenhouses should be given a solution of
balanced fertilizer (20-20-20) once a week during the growing season. Outdoor plants require a heavier
concentration of the same fertilizer. During the non-growing season, apply the same proportions every
two weeks rather than weekly. In addition at every third feeding substitute a blossom booster. This is a
feeding program for all year long.
PESTS: Vandaceous plants seem to have a problem with thrip. These are very small sucking insects
about 1 mm in size. Thrip damage usually occurs on the flowers and buds, causing the blooms to lose
their beauty rapidly. When thrip is a problem, a spraying program must be adhered to as the plants come
into bud. Once the thrips get inside the flower bud, they are somewhat protected from contact sprays. A
fine spray mist should be used to avoid injuring the tender buds. Spray young spikes and buds with a
solution of carbaryl insecticide wettable powder following manufacturer's directions. Scale is another
pest; use an insecticide like malathion. Remember that all these products are intended to kill and should
be used in the open air outside your home. A paraffinic oil, which smothers bugs and their eggs, is
labeled for use in the home. Insecticidal soap is also effective against scale and is safe, but it has less
residual action. With any of these products some insects, and especially their eggs, will survive to breed
again. One dose of even systemic insecticide will not wipe out a large population of insects totally and
completely.
4200 WISCONSIN AVENUE, NW
WASHINGTON, D. C. 20016
202-244-6100
10313 KENSINGTON PARKWAY
KENSINGTON, MARYLAND 20895
301-946-6700
5011 OLNEY-LAYTONSVILLE ROAD
OLNEY, MARYLAND 20832
301-987-1940