Coral Fern, recognized by its delicate, intricate fronds, is a unique plant sought after by garden enthusiasts. Its distinctive appearance, resembling underwater coral formations, adds appealing texture to plant collections. This fern brings lush, natural beauty to indoor and outdoor spaces, making it a popular choice.
Understanding Coral Fern
Coral fern (Gleichenia microphylla) is characterized by finely divided, wiry fronds that create a dense, tangled thicket. These fronds are typically bright green and can fork multiple times, forming a sprawling habit. The fern forms extensive colonies through vigorous, long-creeping rhizomes (underground stems).
Commonly found in tropical and subtropical regions, particularly Australia and New Zealand, its natural habitat includes moist areas like swamps, creek margins, and forests. It thrives in damp, sunny conditions but shows adaptability to more shaded or drier sites.
Coral Fern Care Guide
Light
Coral fern thrives in bright, indirect light, mimicking natural dappled sunlight. Avoid direct sun, which can scorch or yellow fronds. An ideal location is near a north-facing window or an east-facing window for gentle morning sun.
Watering
Consistent moisture is important; coral fern prefers evenly moist soil without becoming waterlogged. Watering twice a week is often sufficient, but check the top inch or two of soil for dryness first. Overwatering leads to root rot, while underwatering causes fronds to brown and crisp.
Humidity
High humidity, ideally above 60%, benefits coral fern, reflecting its native tropical environment. Increase humidity by misting foliage, placing the pot on a pebble tray, or using a room humidifier. Naturally humid areas like bathrooms or kitchens are also suitable.
Soil and Temperature
A well-draining soil mix rich in organic matter is suitable, such as potting bark, sand, and peat for drainage and water retention. Optimal temperatures are typically 18°C to 24°C (65°F to 75°F), with nighttime temperatures not dropping more than 10 degrees cooler.
Fertilization and Repotting
Coral fern is a light feeder, not requiring frequent fertilization. During its active growing season (spring to early fall), apply a balanced liquid fertilizer diluted to half strength about once a month. Repotting into a slightly larger container with fresh potting mix is beneficial when the plant becomes root-bound, usually every two years.
Common Coral Fern Problems
Browning Fronds
Browning fronds often indicate low humidity, insufficient watering, or excessive light. Dry air causes fronds to crisp at the tips. Underwatering leads to crispy fronds, while direct sunlight can scorch leaves. Increase humidity, maintain consistent soil moisture, and ensure indirect light to restore health.
Wilting or Drooping Fronds
Wilting or drooping fronds typically indicate underwatering or root rot from overwatering. Dry soil causes wilting. Waterlogged soil suffocates roots, preventing water uptake and causing wilting. Improve soil drainage and allow the top layer to dry slightly between waterings. Removing brown or mushy roots during repotting can also aid recovery.
Pests
Ferns can be susceptible to common houseplant pests like spider mites, aphids, and mealybugs. Spider mites cause speckling and webbing, thriving in dry conditions. Aphids feed on plant sap, leading to curled leaves. Mealybugs appear as cottony white masses, also feeding on sap and causing yellowing.
Organic treatments include wiping leaves, insecticidal soap, or neem oil. Increasing humidity deters spider mites.
Lack of Vigorous Growth
Lack of vigorous growth might stem from insufficient light or nutrient deficiencies. Stunted growth occurs if the fern doesn’t receive enough bright, indirect light. While ferns are light feeders, prolonged nutrient deficiency hinders development. Provide appropriate light and a regular, diluted feeding schedule during the growing season for healthier growth.
Propagating Coral Fern
Division
Propagating coral fern is most effectively done through division, ensuring new plants retain parent characteristics. This method is simpler and yields faster results than spore propagation for hobbyists. Division is best performed in early to mid-spring, when the plant begins its active growth cycle.
To propagate by division, carefully remove the mature coral fern from its pot, preserving the root system. Identify natural segments within the root mass, characterized by distinct rhizomes and fronds. Using a clean, sharp knife or sterilized garden shears, divide the plant into sections, ensuring each new section has healthy rhizomes, roots, and at least a few fronds.
Replant each divided section into individual pots with a well-draining, moist soil mix rich in organic matter. Plant new divisions at their previous depth. After repotting, maintain consistent soil moisture, avoiding waterlogging, and provide a humid environment to encourage root establishment and new growth. This can be achieved through regular misting or by placing pots in a high-humidity area.
Spore Propagation
While division is the primary method for home growers, coral ferns can also be propagated from spores, though this requires more patience and specific conditions. Spores, found in sori on the underside of mature fronds, can be collected and sown on a sterile, moist medium. Spore propagation is a slower process, with tiny prothalli appearing after several weeks, eventually developing into small ferns over many months.