LIGHT

Light is a crucial factor for the flowering of most Vandaceous plants.

There are two types of Vanda: flat-leaved and terete-leaved. The former type has broader, flatter leaves, while terete-leaved types have round, pencil-shaped leaves. Terete-leaved types require full sun and grow best in climates with plenty of light. In a greenhouse, provide plants with about 25-35% shade, less in winter if the sky is cloudy. Leaves should be a medium green, not dark green. In hot, bright climates, you can grow any type of Vanda outdoors (if it's warm) with partial shade for strap-leaved and semi-terete types (especially at midday in summer) or indoors (when it's cold) in a bright, south-facing window. In climates with cloudy winters, try Ascocentrums. Grow them outdoors in summer and in full sun indoors during winter. Be careful to acclimate plants to avoid sunburn.

Generally, Vandas require bright light, but do not thrive in full sun. They can acclimatize to full sun, but these plants generally appear faded and not as healthy as those grown under a light shade cloth to soften intense sunlight.

TEMPERATURE

Vandas require warm temperatures, with the exception of Vanda coerulea and some of its hybrids. A minimum night temperature of 13 °C is recommended. Optimal temperatures are between 15 °C and 22 °C at night and a maximum of 35 °C during the day. Warmer temperatures result in faster growth, which must be balanced by higher humidity, air movement, and increased watering and fertilization. Days should be warm and humid for optimal plant growth.

The only true exception is Vanda coerulea, one of the few true blue orchids, which can tolerate cold temperatures better than many of its cousins.

WATERING

Vandas are occasionally grown in plastic pots with sphagnum moss and orchid substrate, but this is far from an ideal situation. Most growers prefer to grow Vandas in slatted baskets instead, where the roots are free to dangle towards the ground. Plants grown this way require a lot of water. Water should be given liberally during growth, but the roots must dry out quickly.

During periods of high temperatures, Vandas may need to be watered twice a day. When watering a Vanda, first immerse the plant until the white or silvery roots change color, then wait a few minutes before saturating it again. In general, the plant should remain underwater for a maximum of 8 minutes. Water sparingly in winter or cloudy weather. Severely dehydrated Vandas can be submerged in a bucket of water (simply immersing the entire plant) for a while to rehydrate them.

HUMIDITY

Try to maintain humidity at 65% or higher. 80% humidity is ideal. In tropical climates, this can be easy to achieve. In a greenhouse, this is easier to achieve by using an evaporative cooler. This can also be created by placing a bed of gravel or pebbles directly under the roots, filling it with water. Make sure the roots do not reach the tray and let the sunlight do the rest. Air movement must be strong.

BLOOMING

Vandas bloom all year round, depending on growing conditions. Healthy, happy plants with abundant access to light, heat, and humidity will bloom at any time. Vandas bloom from spikes that emerge in a predictable pattern between the leaves. The flowering spikes feature multiple flowers, depending on the plant, and the flowers will remain open for several weeks.

FERTILIZATION

Vandas are plants that need a lot of nourishment, and well-fed plants bloom better. During the growing season, fertilize weekly with a diluted liquid fertilizer. Plants grown in plastic pots can be fertilized with controlled-release pellet fertilizers, in addition to liquid fertilizer. Fertilize only on the roots or substrate.

Recommended fertilizers:

• Balanced growth fertilizer: 20-20-20 (NPK) – 1 gram per liter of water. Spray once every two weeks (14 days)
• High phosphorus fertilizer for flowering: 0-52-34 (NPK) – 1 gram per liter of water. Spray every two weeks (14 days)

REPOTTING, SUBSTRATE AND PROPAGATION

Vandas are large, robust plants that quickly outgrow most pots. They grow best in situations where large aerial roots can move freely in the air or cling to a substrate.

Large Vandas may not need repotting, as they will continue to grow over the edge of the basket. However, if necessary, repot every 2 years in spring. After repotting, keep the plant in a slightly dry place for the first two weeks to allow any cracked roots to heal. Vandas prefer terracotta pots because they breathe better than plastic.

If you notice the Vanda's roots turning brown or mushy, this indicates rot. Cut these diseased roots from the orchid, leaving only healthy, green, or white roots. Alternatively, cut the dead roots at the base and place the healthy top of the orchid back into baskets or hang it again.

“Vandas grow best in open baskets without substrate”