Blue vanda
The most common mistake with blue vanda (Vanda coerulea) is planting it in dense soil like an ordinary houseplant. This is an epiphytic orchid: its roots need to breathe, get wet quickly, and dry out just as quickly.
Structure of an epiphytic orchid
In the wild, this orchid grows not in soil but as an epiphyte: it anchors itself to trees and keeps its roots exposed to air. The roots are covered in velamen, a spongy layer that absorbs water quickly and also needs to dry out.
This species has a short stem, 5-23 cm long and 0.8-1.5 cm thick. The leaves are leathery, 7-18 cm long and 1.3-3 cm wide, with two unequal lobes at the tip.
| Part | Feature |
|---|---|
| Stem | 5-23 cm long |
| Leaves | leathery, 7-18 cm |
| Inflorescences | 1-3, each 20-42 cm long |
| Flowers | 6-9 cm in diameter |
Origin and natural habitat
The species is native to northeastern India, southern China, and Indochina. In its natural habitat, it grows in open tree canopies, in forests, and near rivers, where its roots receive plenty of air.
This background explains its main requirement indoors: the root system must not stay wet for long. It needs regular moisture, but water collecting around the base of the stem is more dangerous to this orchid than a brief dry spell.
The English name “blue orchid” refers to the sky-blue color of the petals, although the flowers can be white or blue with purple spots.
Plants sold in stores as “vanda” are mostly hybrids. Vanda coerulea is one of their parent species, so a store-bought plant may differ in color from the one described here.
Light and placement
The plant needs bright indirect light. Direct midday sun at a south-facing window can cause burns, so shading with a curtain or roller blind is appropriate in April-August.
Insufficient light is often not immediately apparent: the plant keeps its leaves but does not produce flower spikes. Very dark green leaves usually indicate too little light, while pale or yellowish leaves indicate too much.
- bright indirect light
- shade from midday sun
- supplemental lighting in fall and winter
- ventilation without cold drafts
- gradual acclimation to more sun
Watering and roots
Base watering on the condition of the roots and the temperature, not on a fixed schedule. The roots must dry after being wetted; constantly wet velamen is easily damaged, especially in cool conditions.
For a bare-root plant, alternate thorough wetting with a dry interval. In hot weather, these roots may need daily watering; on cool days, increase the interval.
- immersing the roots in water
- a warm shower followed by drying the leaf axils
- spraying exposed roots
Potting mix, container, and repotting
The plant can be grown with exposed roots, in a hanging basket, or in very coarse bark. Ordinary dense soil is unsuitable: the roots do not get enough air in it.
Sphagnum around the base of the stem is undesirable if it stays wet for a long time. Repot when the bark has broken down, the roots have outgrown the container, or there are signs of rot.
| Option | When to use it |
|---|---|
| Bare roots | with stable humidity and frequent watering |
| Coarse bark | when moisture needs to last longer between waterings |
| Hanging basket | when good air circulation is important |
Flowering, feeding, and propagation
Inflorescences can be 20-42 cm long and carry 4-16 flowers. In the wild, flowering occurs in October-November; indoors, it depends on light, temperature conditions, and root health.
Feed during active growth, usually once a month with an orchid fertilizer solution. A concentrated solution can burn the velamen, so the roots should receive weaker, consistent feeding rather than infrequent heavy doses.
Indoors, the plant is propagated vegetatively by separating side shoots, or offsets. Keep the young plant warm and out of direct sun until it develops its own root system.
Common problems
Most problems stem from two extremes: exposed roots drying out too much in hot weather, or overwatering in cool conditions. Both affect the leaves, growth, and ability to produce flower spikes.
- yellowing leaves caused by excessive sun or root problems
- failure to flower because of insufficient light
- rot at the base after water collects there
- velamen burns from hard water or concentrated fertilizer
- roots drying out in low humidity
After watering or a shower, check the leaf axils: water that remains there for a long time increases the risk of rot. If the plant is in a cool spot, reduce watering and do not leave it wet overnight.
- Light
- bright indirect light
- Temperature
- +18…+30 °C
- Watering
- wet and dry cycles
- Soil
- bark or bare roots
- Difficulty
- high
- Cats and dogs
- safe
- Leaves indoors
- 7-18 cm long
- Native range
- northeastern India, southern China, and Indochina
Care
Blue vanda needs plenty of light, air around its roots, and distinct wet and dry cycles. The main challenge indoors is avoiding overwatering the roots while trying to compensate for low humidity.
- Light
- Provide bright indirect light. At a south-facing window, shade from midday sun is needed in April-August; insufficient light often prevents flowering.
- Temperature
- Keep at +18…+30 °C. This is the range for the growing season. In winter, do not let temperatures fall below +16 °C; reduce watering in cool conditions to avoid rot.
- Watering
- Water once the roots have dried. Alternate thorough wetting with drying. In hot weather, exposed roots may need daily watering; standing water is dangerous.
- Soil
- Use coarse bark or grow without potting mix. The roots need air. Dense soil and wet sphagnum around the base increase the risk of rot.
- Feeding
- Feed once a month. Feed during active growth with an orchid fertilizer solution; an overly concentrated solution can burn the velamen on the roots.
- Support
- Use a hanging basket. A basket or support with good airflow is suitable for exposed roots, keeping water from collecting around the base of the stem.
- Leaves
- Check the leaf axils. After a shower or thorough watering, remove water from the leaf axils, especially in the evening and in cool weather.
- Repotting
- Repot when the bark breaks down. Do not repot on a fixed schedule: decomposed potting mix, a cramped container, or suspected root rot are the signs to look for.
Botany
- Family
- Orchidaceae
- Genus
- Vanda
- Species
- Vanda coerulea
- Author and year
- Griff. ex Lindl.
Blue vanda belongs to the family Orchidaceae and grows as an epiphyte. Its roots are adapted not to dense soil but to an airy environment, where water arrives quickly after rain and disappears just as quickly.
The flowers are 6-9 cm in diameter, white or blue, often with purple markings. The petals and sepals are broad and rounded, and the inflorescence can carry several large flowers on a single flower spike.
Its natural range covers northeastern India, southern China, and Indochina. The species has a chromosome number of 2n=38.
Frequently asked questions
- Why isn't it flowering?
- The most common cause is insufficient light. Flowering also declines if the roots are damaged or constantly wet.
- How do I water a bare-root plant?
- Wet the roots thoroughly, then let them dry. Water bare roots more often in hot weather and less often in cool conditions.
- Can I plant it in ordinary soil?
- No. Dense soil blocks airflow to the roots and increases the risk of rot.
- Is it safe for cats and dogs?
- The plant is safe for cats and dogs. Still, it is best to remove damaged leaves or roots so pets do not chew them.
- When should I repot?
- Repot if the bark has broken down, the roots are not drying out, or there are signs of rot. Repotting this orchid on a fixed schedule when it does not need it is not beneficial.
