Basket Vandas are one of the most popular and sought-after orchids because of its large and beautiful flowers. The Vandaceous group comprises of Aerides, Vanda, Ascocentrum, Rhynchostylis, Arandas and Mokara. The genus has about 60 species and is distributed mainly in the tropical regions of India (Himalayas), especially North-East India and Western Ghats, Indonesia, Northern Australia, China, Philippines, Sri Lanka, Myanmar Thailand, and New Guinea.
Plant: Vandas are monopodial in their growth. It grows from the tip or crown in one direction.
They are epiphytes and the main stem will have several lateral buds, which later develop into plantlets, and each one of these will grow into a big size plant with several aerial roots. Plants have long trailing aerial roots. Depending on the size and shape of the leaf, there are strap leaved, terete leaved and semi terete leaved Vandas.
Light: Vandas prefer high light intensity, particularly terete Vandas which can adapt very well to full sun conditions. On an average Vandas require about 3000-4000 feet candles and some terete leaf
Vandas may need up to 6000 foot candles. Vanda coerulea (Picture 4) and its hybrids are cool growing plants than the other warmer growing Vandas.
Temperature: This genus does well in daylight conditions where temperature is above 25-30° C and night temperature should not go below 12° C. Avoid cold draft for the plants during the cold season.
Water and Humidity: Vanda need frequent watering. Frequent misting and wetting the aerial roots is very essential. Most of the Vandas are grown in hanging baskets and watering is very important in such conditions. Vanda roots absorb moisture much slowly than other orchid roots. In summer months frequently wetting the aerial roots is important, the process involves, wetting them once and again re-wetting them after 5 minutes ensures complete wetting of roots. Vandas require humidity of 50 per cent and above during most of its growth period. Vandas like good air movement as they have a lot of aerial roots.
Nutrition: Vandas are heavy feeders and responds positively to balanced nutrition and watering. Using fertilizers on a weekly basis with half the recommended dose of a balanced fertilizer is advisable (0.5 — 1.0 gram per litre of water). A fertilizer of 19-19-19 on a weekly basis will ensure good growth and flowering. As the plant matures, increase Potash and bring down Nitrogen levels.
Potting and Media: Vandas can attain huge sizes over a period of time. They prefer to be hung in baskets with its aerial roots hanging down. They are also grown in pots and perform well in a porous and well-draining media with proper aeration. Charcoal, brickbats and coconut husk chips are common planting media used.
Pests and Diseases: Fusarium wilt and crown rot are major diseases on Vandas.