General Information
Vandas are native to Southeast Asia. In their native habitat, Vanda orchid plants hang from trees in nearly soilless media. It is important to mimic this condition as much as possible when growing Vanda orchid. Care of Vanda orchids is simple, provided you remember a few key items regarding the orchid’s preferences. Once you have the right growing situation, you can become skilled at how to grow Vanda orchids and enjoy large colorful blooms every few months.
The family of Vanda orchids is all epiphytic, which means the plants cling to tree bark or hand from cracks in cliffs and rocky areas. This means their roots are in relatively little soil, just whatever organic matter the crevasse or crack collected over time. Most varieties prefer bright light and warmth as well as a reasonable degree of humidity. Vanda orchid plants bloom several times a year with 1 to 4 inch blooms in a host of colors. Plants range in size from miniatures to huge flora several feet tall.
Light
Light is a crucial factor in blooming most vandaceous plants. There are two types of vandas: strap-leaved, and terete. The first type has broader, flat leaves, while terete types have round, pencil-shaped leaves. Terete types need full sun, and are best grown in high-light climates. In a greenhouse, give the plants about 25 to 35 percent shade, less in winter if overcast. Leaves should be a medium green, not dark green. In warm, bright climates, you can grow any type of Vanda outside (if warm) with partial shade for strap-leaved types and semi-teretes (especially in midday in summer) or inside (when cold) in a bright, south window. In climates where winters are overcast, try Ascocendas. Grow them outside in summer and in full sun inside during the winter. Be careful to acclimate plants to avoid burn.
Generally Vandas require bright light but generally do not thrive in full sunlight. They can acclimate to full sun, but these plants are generally washed out and not as healthy as those grown under a light shade cloth to take the edge off strong sunlight.
Temperature
Vandas require warm temperatures except for vanda coerulea and some of its hybrids. A minimum night temperature of 55° F is recommended. Optimum temperatures are 15° to 22° C at night, and a maximum of 35° C during the day. Warmer temperatures mean faster growth, which must be balanced with higher humidity, air movement, and increased water and fertilizer. Days should be warm and humid for optimum plant growth.
The only real exception to this is the Vanda Coerulea, one of the few true blue orchids, which can handle cold temperatures better than many of its cousins.
Watering
Vandas are occasionally grown in plastic pots with sphagnum moss and orchid media, but this is a far-from-ideal situation. Instead, most growers prefer to grow Vandas in slotted baskets, where their roots are free to dangle toward the ground. Plants grown like this require a great deal of water. Water should be applied copiously when the plants are growing, but the roots must dry quickly.
In periods of high temperatures, Vandas might need to be watered twice a day. When watering a Vanda, first soak the plant until the white or silvery roots turn color, then wait a few minutes before again saturating the plant. Overall, the plant should be under the spray for up to 8 minutes. Water sparingly in the winter or during cloudy weather. Seriously dehydrated Vandas can be floated in a bucket of water (just put the whole plant in) for a while to rehydrate them.
Humidity
Try to maintain 65% and above. Humidity of 80 percent is ideal. In tropical climates this may be easy to obtain. In a greenhouse, this is easier to provide by using an evaporative cooler. Make your own evaporative cooler by placing a bed of gravel or pebbles directly underneath the roots and fill it with water. Make sure the roots does not reach the tray and sunlight does the rest. Air movement must be strong.
Blooming
Vandas will bloom throughout the year, depending on their growing conditions. Healthy, happy plants with plenty of access to light, warmth, and moisture will bloom at any time. Vandas bloom from spikes that emerge in a predictable pattern from between leaves. The flower spikes have multiple flowers, depending on the plant, and the flowers will stay open for a matter of weeks.
Feeding
Vandas are heavy feeders, and well-fed plants bloom better. During the growing season, fertilize weekly with a liquid-based, weak fertilizer. Plants that are grown in plastic pots can be fertilized with controlled-release fertilizer pellets in addition to the liquid-based fertilizer. Fertilize only over roots or substrate.
Recommended Fertilizers:
Balanced Fertilizer for Growth: 19-19-19 (NPK) – 2 grams per litre of water – Spray once in every alternative week (14 Days)
High-Phosphorus Fertilizer for Blooming: 0-52-34 (MPK) – 1 gram per litre of water – Spray on every alternative week (14 Days)
Potting, Media and Propagation
Vandas are big, robust plants that will quickly outgrow most containers. They do best in situations where the large aerial roots are allowed to meander through the air or grasp onto a substrate.
Large Vandas might not need repotting at all, as they will continue to grow beyond the edge of the basket. However, if required repot every 2 years in spring. After repotting, keep the plant a bit on the dry side for the first couple of weeks as this allows any cracked roots to heal. Vandas prefer clay pots as they breathe better than plastic.
If you notice vanda roots turning brown or mushy, this indicates age or rot. Trim these bad roots off the orchid, leaving only healthy green or white roots. Alternatively, cut off the dead roots at the bottom and re-basket or rehang the healthy top portion of the orchid. This is also a good time to divide your vanda orchid, if you want to grow more. When you see three or more roots growing from your orchid, cut between two of them to divide the vanda in late spring or early summer.
“ Vandas are Best Grown in Open Baskets without Media”
Alternative Planting Methods
If you're growing your vanda orchid outside, you can tie the roots to a tree branch with cotton string, which decomposes over the course of about a year, the same amount of time it takes for orchids to attach their roots to the tree permanently. Another option that works inside the house as well as outdoors is attaching the roots to a cork slab and hanging it on a wall, or simply mounting the orchid on a wire hanger.
Pests and Other Vanda Related Problems
Fungal and Bacterial Diseases of Vandas are common because of the high levels of humidity they need to survive. Fungal agents cause problems like root rot, leaf spots, leaf blights and spots on flowers.
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