Vanda coerulea

Growing in Pots, Balconies & Indoors

Vanda coerulea can be kept indoors, but the grower stresses it needs a lot of light by a window – it is a sun-hungry orchid, so only a very bright, sunny windowsill will do, not a shaded room. These orchids grow best with their roots open to the air, mounted or in a basket rather than packed in soil.

Quick Details

• Container Size: 20-60 cm (12-24 in)
• Indoor Suitability: Only on a very bright, sunny windowsill (a lot of light by a window)
• Best Spot: Full sun to half shade – as much bright light as possible
• Soil & Drainage: Best grown bare-root on bark or a synthetic mount; if potted, only very coarse orchid medium
• Watering in Pots: Water/mist generously and often; the exposed roots dry quickly and like high humidity

Indoors & On the Windowsill

• Windowsill only: The grower says indoors is possible only right at a window with a lot of sun – Vanda coerulea will not thrive in the low light of a room interior.
• Bright sill: Give it your sunniest window and keep humidity up around the bare roots with regular misting.
• Overwintering: Not frost-hardy – keep it in the brightest indoor spot over winter in cold climates.

On a Balcony or Patio

• Light & humidity: Outdoors it loves bright light and warmth, but hanging baskets and bare roots dry out fast – mist and water often, especially against warm sunny walls.
• Bring it in: Return it indoors before cold nights; it is a tender, tropical orchid.

Choosing the Pot, Soil & Long-Term Care

• Basket or mount: These orchids grow best with their thick roots open to the air – in a slatted wooden basket, or mounted bare on a slab of bark or a synthetic support rather than packed in soil.
• If potted: Use a clear pot with big drainage holes so you can check the roots, and only a very coarse, chunky medium (big bark or coconut chunks). Keep the humidity high and never let water sit at the base.
• Feeding: Feed little and often with a dilute orchid fertiliser through the growing season; open, airy roots take up nutrients quickly.
• Refresh: Renew part of the medium each year, or all of it about every two years as it breaks down.

Grower’s Container Tip

• Grow it bare: The grower prefers to grow it with nothing around the roots – on a slab of bark or a synthetic mount – rather than in a pot of medium, so the thick aerial roots get the air they want.

Bloom & Flower Guide

Quick Details

• Bloom Season: Most of the year; in cooler places it pauses in winter
• Flower Appearance: Large, flat, rounded flowers of five petals, blue or blue-purple over white, marked with a distinctive checkered pattern
• Edibility: Ornamental — grown for its flowers, not eaten (orchid foliage and flowers are generally non-toxic)

Detailed Blooming Overview

The Blue Vanda is one of the most celebrated of all orchids, famous for a colour that is genuinely rare among flowers. The grower describes rounded petals of blue or purple over white, patterned with squares — the beautiful net-like or checkered marking that runs across the bloom. Large and long-lasting, the flowers can appear over much of the year in warm conditions, resting in winter where it is cool.

Flower Characteristics

• Five rounded petals in blue or blue-purple over white (grower’s description).
• A striking checkered or net-like pattern of darker squares over the paler ground.
• Flowers are large, flat and long-lasting, several to an upright spike.

Bloom Care & Thinning

• Triggering bloom: Very bright light with high humidity and free root watering brings the best flowering; this species also enjoys slightly cooler nights than many Vandas.
• After flowering: Cut the spent spike to the base and keep feeding the vigorous roots.
• While in spike: Maintain high humidity and steady warmth so the buds develop their full colour.

Bloom Health & Protection

• Botrytis petal blight can spot open flowers with small brown or translucent marks in cool, damp, still air — better ventilation and keeping water off the blooms is the first line of defence, with a fungicide only if it spreads.
• Aphids, scale and mealybugs are drawn to soft buds and flower spikes — wiping them off or treating with neem oil or insecticidal soap keeps the flowers clean.
• Bud blast (buds yellowing and dropping before they open) is usually a stress response to sudden changes in temperature, light or humidity, or to dry air — steady conditions while the plant is in spike prevent it.