Cooktown Orchid (Dendrobium bigibbum)

Dendrobium bigibbum, commonly known as the Cooktown Orchid, is a striking epiphytic or lithophytic orchid native to tropical North Queensland, Australia, and parts of New Guinea. This species is renowned for its vibrant, long-lasting flowers and is the progenitor of many popular hybrid orchids.

Features:

Dendrobium bigibbum features slender, cylindrical pseudobulbs that can reach up to 1.2 meters (4 feet) in length. Each pseudobulb typically bears 3 to 12 egg-shaped leaves, approximately 8–15 cm (3–6 inches) long. The orchid produces arching inflorescences, 20–40 cm (8–16 inches) long, adorned with 2 to 20 lilac-purple flowers, each measuring 2–3 cm (0.8–1.2 inches) across. The flowers are resupinate, meaning they are oriented with the lip facing downward, a characteristic feature of many orchids.

Care Tips:

Light

• Requirement: Bright, indirect light

• Note: Avoid direct sunlight, which can scorch the leaves.

Temperature

• Daytime: 70–85°F (21–29°C)

• Nighttime: Slight drop to 60–65°F (15–18°C)

• Humidity: 50–70%

Watering

• Growing Season (Spring–Summer): Water copiously, allowing the medium to dry slightly between waterings.

• Dormant Season (Fall–Winter): Reduce watering frequency, but ensure the plant does not dry out completely.

Medium

• Type: Well-draining orchid mix, such as bark chips, coconut husk, or a blend with perlite and small stones.

Fertilization

• Growing Season: Apply a balanced orchid fertilizer weekly at 1/4 to 1/2 the recommended strength.

• Late Summer–Autumn: Switch to a phosphorus-rich fertilizer to support blooming.

Repotting

• Frequency: Every 1–2 years, preferably in spring.

• Medium: Use fresh, well-draining orchid mix.