Vanda Alliance Culture
Common Name: Orchid
Vandas and its alliances are generally warm growing orchids. They are found in tropical Asia, and are easily grown in
warmer climates. The smaller growing ascocendas are best outside tropical conditions.
are best grown warm, with minimum winter night
temperatures of 12 C, they will tolerate colder temperatures, provided there is no draughts. The recommended temperatures are 15 C at night to about 35 C in the day. They also tend to grow faster when kept warmer, but it must be remebered to increase the humidity and air flow if the temperatures are increased.
This is critical for blooming
most vandaceous plants. Vandas can be devided into three
types, namely: strap-leaved, semi-terete
and terete. The strap-leaved type has broader, flater
leaves, while terete types have round,
pencil-like leaves. The semi-teretes are
intermediate between the two. The terete types need to be grown in full sun.
The leaves should be a medium green,
not dark green. If they are dark green, give them more light.
Watering and Humidity
My Vandas are grown at around 50% to 80% humidity, with constant air movement. Humidity is always a problem, getting the right mix is difficult, you can raize the hummidity is a few ways, for example by placing flat trays filled with stones and then partially filled with water, and standing the pots on top of the stones. In a greenhouse, I put down a sheet of plastic, and then gravel ontop of that, and everyday I flood the floor, this increases the humidity to the correct amount. You can also use an evaporative cooler, and a misting system. Cultured Orchids obtain water in two ways, one is by the humidity in the air, the other is by watering directly in the pot. I water my orchids from the fish pond and they seem to love it. You will have to learn from your orchids when to water them, it is difficult to say that they should be watered every 3rd or 4 th day, because this depended on several factors, such as potting mix, humidity, type of pots and quality of water. I was once told, " if in doupt, wait another day..."
Repotting and Potting mixes
There is a wide range of mixes available at present. Cattelyas will grow in anything from tree bark to stones. There are various potting mediums, such as osmunda (expensive), tree fern, bark, moss, CHCs (coconut husk chips), perlite, vermiculite, Semi-Hydro (used in the hydroponics industry) sponge rock and rockwool (extruded melted rock). It must just be remembered that whatever medium you use, it should be a free draining one. I grow may Vandas in slatted baskets or mounted on a stick.
Must be done on a weekly basis. It is recommended that you use a balanced 20-20-20 fertiliser at the full recommended strength in warm weather and a quater strength during cloudy and cooler weather. You can use a high-phosphorus fertilizer 10-30-20 every third application
to promote flowering.