Vanda coerulescens aka Periwinkle Pinwheel

Vanda coerulescens, or sky blue vanda, is an evergreen orchid. It belongs to the orchid family, Orchidaceae. Its native range runs from Arunachal Pradesh to Yunnan and northern Thailand. It grows in the wet tropics as an epiphytic subshrub. This means it grows on other plants for support.

Plants reach about 3.3–4.9 feet (1–1.5 metres) tall in cultivation. Their spread reaches 1.6–3.3 feet (0.5–1 metre). They take five to ten years to reach full size. This monopodial orchid grows upward from one main growing point. Leaf sheaths cover the central stem. The green to dark green leaves are leathery and strap-shaped. Deep grooves run along them. Lower leaves fall as fresh leaves form above. New roots emerge straight from the rising stem.

Flower stems arise where leaf sheaths meet the stem. They can reach 2–3.3 feet (0.6–1 metre) long. Each carries many small, waxy flowers that last well. The petals and sepals narrow at their bases. The RHS describes white, pale purple, or pink flowers. Their small lip tends to have a darker shade. Chicago Botanic Garden lists blue, lavender, and purple blooms. It records flowering in January and February. The plant suits display as a specimen orchid.

Give this orchid strong light, but shield it from midday sun. A bright greenhouse or conservatory suits its needs. The RHS gives a winter temperature near 59°F (15°C). Summer temperatures may rise to 86°F (30°C). It rates the plant H1A, for year-round growing under glass. Chicago Botanic Garden lists USDA zones 12–13. Grow it in an open basket or coarse bark-based orchid mix. Keep the roots moist, with free drainage. Aim for 70–80% humidity and good airflow. Mist during active growth and feed from spring through autumn. Reduce misting during winter rest, without leaving roots dry for long.

Scale insects and mealybugs may attack the plant. Thrips can harm both buds and open flowers. Disease is uncommon, but poor airflow can lead to rot. Clean tools help limit the spread of plant viruses. Cut spent flower stems back to their bases. Mature plants may form side shoots called keiki. These can grow separately once they have enough roots. Seed propagation needs controlled laboratory conditions.