Growing Vanda Orchid
A favorite of orchid hobbyists, Vanda orchids are taking their place among traditional houseplants in homes across the country. The members of this group of orchids enjoy warmth and bright light and easily make the transition to the outside patio or deck in the summer. Because they produce long-lasting, showy blooms several times a year, they are highly valued.
Height and Spread
Typically vandas are large in size, growing as tall as 3 feet. Their leaves extend several inches on either side of their central stem making the plant 14 to 16 inches wide.
Flowers
Vanda flowers bloom several times over a year, sometimes continuously. They appear in clusters along narrow stems that emerge along the main stem between the leaves. Individual blooms, from 2 to 4 inches across, are typically round and flat and are sometimes nicknamed “moon orchids”. They are available in various shades of pink, white, purple, blue, brown and blends of these colors. Many vandas feature flowers that are marbled with darker shades of color.
Foliage
Vanda leaves are narrow, and strap like. They grow opposite each other along an upright central stem, creating a ladder like appearance. They are medium to light green and have smooth edges.
General Plant Care
Light and Temperature
Vandas like strong light, even full morning sun if possible. Outdoors in the summer their leaves need some shade in the afternoon when the sun is hottest. They can handle temperatures from daytime 70-80s down to 50 or below at night.
Potting
Vandas are epiphytes, meaning that they have aerial roots which allow them in the wild to take their nutrients and moisture from the surrounding atmosphere. Special structures in the roots enable them to absorb the minerals in dew and rain and support fungi that provide nutrition. Not dependent on soil, in their native habitats they grow above the ground and are capable of grasping tree limbs, pieces of bark, or other structures with their roots. They like to be suspended, their roots hanging freely. It is not necessary to plant vandas in a pot with soil or other potting medium. While they will manage fine in a pot with coarse bark, charcoal, lava rock or chunks of tree fern, they do equally well, if not better, with their roots uncovered in open basket type containers. Basically they do not like to have their roots disturbed, so repot them or train them to a larger basket as infrequently as possible. The only time repotting is necessary is when the medium has completely broken down and rots, risking disease or when the plant has truly outgrown the pot. Air roots will extend out of the pot routinely and are not a sign that repotting is necessary.
The best time to repot is April or May. Soak plants that are to be repotted or put in a larger basket for a few minutes prior to disturbing them. Then gently extricate those that are rooted in medium in conventional pots and allow them to soak for 5 minutes in a solution of vitamins/hormones and fungicide.Then introduce them to their new container. Set the vanda in the center of the pot, the base of its central stem resting on the bottom of the pot. Fill in and around the roots with potting medium, taking care to fill all large spaces.
The top level of the medium should come up to just below the first leaves of the vanda. Be sure the plant is firmly supported in its new pot so that it will develop a strong root system. If it wobbles, stake it temporarily. Those vandas already established in shallow baskets or slatted boxes can be easily repotted by simply setting the original container inside the new, larger one. Weave the damp, softened roots through and around the edges of the larger container so that the vanda is supported upright. Set newly potted plants in a more shaded area temporarily while they recover from the shock. Limit watering for a day or two.
Watering and Humidity
Vandas orginate in tropical areas where moisture is constantly available to their aerial roots (described above), so they are capable of year round bloom. Although they have periods where the plant does not grow, they not have a dormant season as such. Therefore in homes and hobby greenhouses they must be watered regularly, their roots drenched and the water allowed to drain through and away. They do not like to stand in water. Humidity is important for these tropical plants, so in dry homes it is wise to mist them once or twice a day, or, better yet, use a room vaporizer or humidifier to raise the humidity in the room.
Locate vandas in humid areas of the home such as the kitchen or bathroom, or set them in a shallow tray with stones, shells or aquarium gravel that can be kept moist to provide humidity. If they are outdoors in the summer in bright light they will need misting several times.
Feeding
Because they bloom frequently and unlike some types of orchids do not have any way to store nutrients, vandas require regular feeding. Once a feeding routine is established, it is important not to vary it. Choose one of the fertilizer products for orchids available commercially.
These are water soluble an can be used once a week or more when watering. Dilute them in water according to instructions on the product label. To avoid the build up of salts on plant roots, flush the vanda containers with fresh water every month or so. It is possible to cut back on both watering and feeding during non-growth periods
Design Considerations
Vandas make excellent container plants for deck, patio, balcony or poolside. In frost-free climates they do well planted in gardens, especially rock gardens.
Propagation
Mature vanda orchids produce small plantlets from inactive side buds on the main stem. After they a year or so, these side shoots can be cut off from the mother plant and established in a pot or basket on their own. They will flower in their third year.
Possible Problems
| Symptom |
Probable Cause |
| Orchid Grows Well; No Bloom |
Too Little Sun |
| Rough Blistered Spots on Leaves |
Sunburn |
| Plant Sickly |
Crust on Clay Pot |
| Leaves Pale; Yellowed |
Lack of Nitrogen |
| Ragged Holes in Leaves |
Slugs or Snails |
| Leaves And Stems Encrusted With Small Bumps |
Scale Insects |
| Leaves Streaked |
Orchid Mosaic |
| Bloom Color Shows Blotches |
Flower Break |
| Ringed Yellow Spots on Leaves |
Ring Spot |
Rough Blistered Spots on Leaves Are Caused by Sunburn
When orchid foliage develops large, rough spots that appear scalded and which turn black they have had too much direct sun. Typically the black spots develop yellowish edges, anywhere from a few days to several weeks they dry to hard, papery spots. Keep newly repotted orchids in light shade for several days. Shield vandas that are outdoors in the summer from the hot afternoon sun.
Plant Sickly, Crust on Clay Pot Buildup of Fertilizer Salts
Because vandas are heavy feeders and therefore require frequent feeding, there is a tendency for the salts in the fertilizer to accumulate and build up on the potting medium and on the pot. They affect plant nutrition over time. Flush the medium and roots repeatedly with clear, warm water to rinse away the salts. In extreme cases, repot with fresh medium in a clean container. Wash old container with vinegar and water, rinsing repeatedly to remove imbedded salts.
Leaves Pale, Yellowed Lack of Nitrogen
Orchids growing in fir bark need higher nitrogen fertilizer because a fungus on the bark steals nitrogen.
Ragged Holes in Leaves Slugs or Snails
The dark, damp conditions around the roots of orchids are very attractive to slugs and snails who nibble root tissues during the day and attack buds and foliage at night. They chew large ragged holes in leaves and stems. Slugs are similar to snails except they have no shells. They are usually 1 to 2 inches long (some species grow up to 8 inches). Their coloration runs the gamut, including <N>white, gray, yellow, and brown-black. Slugs and snails are attracted to moist, well-mulched gardens and acidic soil. Orchids that are set out in the garden may fall victim to these pests.
The best strategy is to simply wait until dark when the slugs are likely to attack plant foliage and handpick them. Hang vandas to avoid their contact with soil in the yard.
Leaves And Stems Encrusted With Small Bumps Scale Insects
Scale insects are covered by rounded waxy shells which protect them while they feed on plant tissues. These shells are visible as bumps, colored white, yellow, or brown to black, on leaf or stem surfaces. They are about 1/10 to 2/5 inch in diameter. The first sign of a scale attack is often discoloration of the tops of the leaves, followed by leaf (drop)and stunted growth. Some species of scale insects excrete a noticeable sticky honeydew which coats affected foliage. Sometimes it, in turn, attracts ants or sooty mold, a gray to black coating on the leaves and stems. Heavy scale infestations can kill orchids. Handle mild scale infestations by simply scraping the telltale bumps off plant surfaces with a fingernail, or cotton swab dipped in rubbing alcohol. Heavy infestations require spraying. Use a mixture of alcohol and insecticidal soap every 3 days for 2 weeks. Add 1 tablespoon of alcohol to to a pint of ready to use commercial soap spray.
Cottony Masses on Plant Parts Mealybugs
Mealybugs are 1/5 to 1/3 inch long, with oval, flattened bodies. They are covered with white waxy powder and adorned with short, soft spines around their edges. These insects sometimes gather in cottony white masses on orchid roots, stems, branches and leaves, sucking sap and reducing the plant<@146>s vigor. Infested leaves look yellowish; severely infested plants are unsightly, do not grow well, and may die. Honeydew secretions from the insects<@146> feeding encourage mold growth on the foliage and attract ants. Control mealybugs by spraying them with an alcohol-insecticidal soap spray every 2 to 3 days until the pests disappear. Add 1 tablespoon of rubbing alcohol to a pint of ready to use commercial insecticidal soap mix.
Leaves Streaked Orchid Mosaic
This virus causes both pale and dark streaks to appear on orchid foliage. These streaks parallel the veins of Cattleya foliage and others. There is no treatment for this disease. Destroy infected plants as soon as diagnosis is confirmed to prevent its spread. Sterilize all tools in a solution of household bleach and water after use on the sick plant.
Bloom Color Shows Blotches Flower Break
This virus causes blossoms of cattleya and some other types of orchids to develop uneven blotches. The color on flower petals is not uniform. There is no cure for this disease. Destroy infected plants. Sterilize all tools in a solution of household bleach and water after use to avoid spreading the virus.
Ringed Yellow Spots on Leaves Ring Spot
This virus causes yellow or brownish ring shaped spots on orchid leaves. There is no cure for this disease. Destroy infected plants to prevent the spread of the virus. Sterilize all tools in a solution of household bleach and water.
Products for Growing Orchids
