The tarantula fern is a captivating houseplant that adds a distinctive touch to any indoor space. Its rhizomes, covered in fine hairs, spread across the potting medium, resembling a tarantula’s legs. This unique appearance, along with its delicate, lacy fronds, makes it a popular ornamental choice.
Understanding Your Tarantula Fern
The botanical name for the tarantula fern is Davallia canariensis. Other Davallia species, like Davallia fejeensis, are also called “tarantula fern” due to their fuzzy rhizomes. This fern features thick, scaly rhizomes that creep along the soil surface or over the pot edge. Its deep green, finely divided fronds can grow to about 50 cm (20 inches) in height.
The tarantula fern is an epiphytic or lithophytic plant in its natural habitat, growing on other plants or rocks rather than in soil. It is native to the western Mediterranean, including the Canary Islands, Madeira, and parts of the Iberian Peninsula. There, it thrives in cool, humid environments, absorbing moisture and nutrients from rainfall and humid air.
Caring for Your Tarantula Fern
Light
Tarantula ferns prefer bright, indirect light. An east or north-facing window is suitable, providing adequate brightness without harsh direct sunlight. Direct sun can scorch fronds, causing a crispy, pale appearance. Insufficient light may slow growth and cause fronds to yellow.
Water
Consistent moisture without waterlogging is important. Water when the top inch or two of soil feels dry. Overwatering leads to yellowing fronds and root rot, while underwatering causes limp or crispy fronds. Avoid directly soaking the fuzzy rhizomes when watering, as this can encourage rot; instead, focus on the potting medium.
Humidity and Temperature
These ferns thrive in high humidity, ideally 60-70%. Low humidity can cause frond tips and edges to brown. To increase humidity, place the pot on a pebble tray, group plants, or use a room humidifier. Misting fronds and rhizomes daily with room-temperature, lime-free water can also help.
Tarantula ferns prefer stable, warm temperatures, generally 16°C to 24°C (60°F to 75°F). They tolerate occasional drops but avoid exposure below 10°C (50°F) or above 27°C (80°F) for extended periods. Protect them from cold drafts and sudden temperature changes, such as those near vents or fireplaces.
Soil
A well-draining, airy potting mix rich in organic matter is suitable. A blend of peat, perlite, and pine or orchid bark provides necessary drainage and aeration while retaining moisture. Ensure rhizomes are not buried, as they grow on the surface and can rot if covered.
Fertilizer
During the active growing season, tarantula ferns benefit from regular fertilization. Apply a balanced liquid fertilizer, such as a 10-10-10 formula, diluted to half or quarter strength, every 4 to 6 weeks. Reduce or suspend fertilization during cooler, dormant months to prevent salt buildup and weak growth.
Propagating Tarantula Ferns
Propagate tarantula ferns through rhizome division, best done when repotting, usually in spring. Carefully remove the fern from its pot and identify natural separations within the rhizome network. Use clean, sharp scissors or a knife to cut a section, ensuring each new piece has at least one growing tip, fronds, and roots.
Plant divided rhizome sections in suitable potting mix, ensuring fuzzy rhizomes remain on the surface. High humidity is important for newly divided plants to establish new growth. Placing potted divisions in a mini-greenhouse or covering them with a clear plastic bag helps create the needed humid environment.
Addressing Common Tarantula Fern Issues
Brown frond tips or edges often signal insufficient humidity or inconsistent watering. Increase ambient humidity with pebble trays or humidifiers. Consistent soil moisture, without complete drying, also prevents browning.
Yellowing fronds can indicate overwatering, nutrient deficiencies, or excessive direct light. If soil is soggy, allow it to dry more between waterings. If lighting is too intense, move the plant to a spot with indirect light.
Limp or drooping fronds usually point to underwatering or root problems. If soil is dry, thorough watering should revive the plant. If soil is wet and fronds still droop, it might suggest root rot from overwatering; improve drainage or repot. A general lack of growth can result from insufficient light, inadequate nutrients, or temperatures outside their preferred range. Ensure proper light exposure and consistent, diluted fertilization during the growing season for healthier growth.
Tarantula ferns can occasionally encounter common houseplant pests like spider mites or mealybugs. Regular inspection of fronds and rhizomes helps detect infestations early. Treat with organic methods such as neem oil or insecticidal soap, following product instructions, to manage these pests.