Microsorum thailandicum, commonly referred to as the Blue Oil Fern, is a rare epiphytic or lithophytic fern native to Southeast Asia, including Thailand, Vietnam, and southern China. It is renowned for its iridescent blue-green fronds, which exhibit a metallic sheen due to specialised surface structures that reflect light. The fronds are strap-shaped, leathery, and can grow up to 20 cm in length and 2 cm in width. This fern typically grows in humid, shaded environments, such as limestone cliffs and tropical forests
The Blue Oil Fern thrives in warm temperatures and high humidity, making it well-suited for cultivation in terrariums or bathrooms where humidity levels are naturally higher. Its unique colouration is most pronounced under low to moderate indirect light conditions.
Native to: Southeast Asia, including Thailand, Vietnam, and southern China. It naturally occurs in humid, shaded environments, such as limestone cliffs and tropical forests.
Water: Maintain consistently moist but not waterlogged soil. Water when the top 2–3 cm of the substrate feels dry to the touch. Ensure the pot has adequate drainage to prevent root rot.
Light: Prefers low to moderate indirect light. Avoid direct sunlight, which can scorch the leaves. The iridescent blue colouration is more pronounced under lower light conditions.
Humidity: Requires high humidity levels, ideally between 60% and 80%. Increase humidity by using a humidifier, placing the plant on a pebble tray with water, or grouping it with other plants. Due to its humidity needs, Microsorum thailandicum is also suitable for terrariums.
Temperature: Thrives in temperatures between 18°C and 24°C. Protect from temperatures below 15°C and avoid sudden temperature drops. Keep away from cold drafts and heating vents to prevent stress.
