Vanda Alliance Care Sheet
Vandas and Ascocendas are no more difficult to grow than other orchids, but they do have special cultural needs for best results. They come from the warm islands of the South Pacific, so they like bright light, warm temperatures, and lots of humidity. Other genera in this alliance are Neostylis, Ascocentrum, Renanthera, and Neofinetia just to name a few. Intergenerics like Darwinara are also included.
Since Vandas grow and flower throughout the year, they don't have a rest period. As long as temperatures are warm enough to keep the roots in active growth you should continue to feed and water as normal. They appreciate an application of water-soluble fertilizer mixed per package instructions and applied to the plant after every third or fourth watering. As with all orchids, water thoroughly before fertilizing.
As Vandas outgrow their containers, they can be set in larger baskets without disturbing the roots. The size of the container is not as critical to the growth of the plant; however, as many of the Vanda roots hang in mid air. We are growing many of our standard sized Vandas and Ascocendas in cedar baskets with no potting medium other than the basket. Miniature and compact hybrids can be easily maintained in pots with a very open free-draining medium. These miniatures also will flower with less light than their larger counterparts. Most Neofinetias, Darwinaras and similar compact crosses can be happily grown in a sunny windowsill.
Vandas are not particularly susceptible to pests or disease. If scale insects are detected, spraying or dipping the plant with an appropriate insecticide such as Orthene 50WP powder (2 teaspoons per gallon of water) twice over a ten-day period should stop the problem. In the greenhouse, fungal spotting of the leaves may occur. A light application of fungicide will usually control the spotting.
If Vandas are grown as houseplants, they appreciate spending the warmer months outside. They like bright light, but the leaves will burn if they go directly from indoor conditions to full sunlight. Vandas need less water in the fall and winter but may be watered most mornings in the summer, especially when grown outside under trees.