Pellaea rotundifolia (Button Fern)

Pellaea rotundifolia, commonly known as button fern due to its round, button-like leaves, is a distinctive fern species that offers a unique aesthetic to plant collections and garden settings. It has adapted to various environments, showcasing its resilience and versatility.

Pellaea rotundifolia – Button Fern: An In-depth Look

Pellaea rotundifolia is characterized by its compact size and arching fronds, which bear small, round, dark green leaves. The leaf stalks will turn a deep red as the plant ages. The contrast between the dark leaves and the red stems adds an appealing visual texture to its appearance.

Native: Native to Australia and New Zealand, this fern thrives in rocky and dry areas, which is quite different from the moist, dense habitats where many other ferns are found. In its native habitat, it is often found in rocky crevices, cliff sides, and moist forests. It belongs to the brake family (Pteridaceae) along with Adiantum (Maidenhair Fern).

Plant Type and Habit: As a terrestrial fern, the Button Fern is a compact, evergreen fern forming a rosette of pinnate fronds to 10 inches (25 cm) long that can add a structured yet soft appearance to indoor and outdoor spaces.

Size: It generally reaches about 6-12 inches in height and spread (15-30 cm), making it an ideal size for container gardening or as an understory plant in shaded garden areas.

Foliage: The foliage is the main attraction with its rounded, glossy, deep green leaflets on dark reddish-brown stems.

Hardiness: This fern is hardy in USDA zones 9-11.

Award: Recipient of the prestigious Award of Garden Merit of the Royal Horticultural Society.

Uses: The Button Fern is an ornamental plant that can be grown indoors or in shaded outdoor settings. Its drought tolerance makes it suitable for rock gardens and complements other drought-resistant plants.

Toxicity: Pellaea rotundifolia is not known to be toxic to pets or humans, making it a safe addition to homes and gardens.

Drought: Unlike many ferns, the button fern exhibits a degree of drought tolerance. However, it still prefers consistent moisture for optimal growth.

Invasiveness: This fern is not considered invasive. Its growth habit is well-contained, making it a manageable plant for a variety of settings.

Benefits: Besides its ornamental value, Pellaea rotundifolia can help purify the air and increase humidity levels in indoor environments, contributing to a healthier living space.

Button Fern Care

Caring for the Button Fern requires understanding its native habitat and replicating those conditions as closely as possible.

Indoor Care

Light: When grown indoors, Button Fern prefers bright, indirect light. Avoid direct sunlight, which can scorch its delicate leaves. An ideal spot is a north-facing window or a spot that receives filtered light through sheer curtains.

Soil: A well-draining, peat-based potting mix is suitable. You can mix standard houseplant soil with perlite or vermiculite to improve drainage.

Water: Keep the soil consistently moist but not waterlogged. Water when the top inch of soil feels dry to the touch. Button Fern is sensitive to chlorine and salts in tap water, so using rainwater or distilled water is preferable.

Humidity: As a tropical plant, it enjoys high humidity. You can increase humidity by placing the pot on a tray filled with pebbles and water, misting the plant regularly, or using a humidifier.

Temperature: It thrives at average room temperatures between 60°F to 75°F (15°C to 24°C). Avoid placing it near drafts or heat sources.

Feeding: Fertilize lightly during the growing season (spring and summer) with a balanced, liquid houseplant fertilizer diluted to half strength. Do not fertilize in the fall and winter.

Outdoor Care

Light: Outdoors, plant your Button Fern in a location that receives partial shade. Too much direct sunlight can damage its leaves.

Soil: In the garden, ensure the soil is rich, well-draining, and slightly acidic. Amending garden soil with compost or peat moss can help achieve the right conditions.

Water: Maintain consistent soil moisture, especially during dry periods. Mulching around the plant can help retain soil moisture and reduce watering frequency.

Temperature and Hardiness: Button Fern is hardy in USDA zones 9-11. In cooler climates, it should be grown in containers that can be brought indoors during the winter months or treated as an annual.

General Outdoor Care: Keep an eye on environmental conditions, especially during extreme heat or cold. In regions where the Button Fern is not hardy, consider growing it in a shaded patio area where it can be easily moved indoors if necessary.

Button Fern Propagation – A Step-By-Step Guide

Propagating the Button Fern by division can be an enjoyable way to expand your collection or share with fellow plant enthusiasts.

Choose the Right Time: The best time to propagate Button Ferns is during the spring or early summer when the plant is actively growing.

Remove the Plant: Carefully take the Button Fern out of its pot. Gently shake or brush off excess soil from the roots so you can clearly see the plant’s structure.

Divide the Plant: Look for natural divisions in the root system where the fern appears to have formed distinct clumps. Using a sharp knife or a pair of scissors, cut the root ball into sections, ensuring each new section has a portion of the roots and several fronds.

Pot Up the Divisions: Fill small pots with a suitable potting mix. Plant each division at the same depth it was growing previously. Gently firm the soil around the roots and water well to settle the soil and eliminate air pockets.

Care After Propagation: Place the newly potted divisions in a location where they will receive bright, indirect light. Maintain high humidity around the plants, either by misting regularly, using a pebble tray, or placing a humidifier nearby. Keep the soil consistently moist but not waterlogged.

Monitor Growth: In the weeks following propagation, watch for new growth as a sign that the divisions are establishing themselves. Continue providing optimal care conditions to support their development.

Button Fern: Pests, Diseases, Common Problems

The Button Fern is generally easy to care for, but like all plants, it can encounter pests, diseases, and common problems.

Pests

Spider Mites: These tiny pests thrive in dry conditions and can cause the leaves to look speckled and dull. If an infestation occurs, increase humidity around the plant and treat it with insecticidal soap or neem oil.

Mealybugs:  Identified by their cottony white appearance, they suck sap from the plant, weakening it. Remove them manually with a cotton swab dipped in alcohol or use insecticidal soap.

Scale insects: Hard or soft-bodied insects that attach themselves to the stems or leaves, causing yellowing and growth stunting. Scrape off with a fingernail or use a cotton swab dipped in rubbing alcohol. Insecticidal soap or neem oil may also be used.

Aphids: These small, sap-sucking insects can cluster on new growth or the undersides of leaves, causing yellowing or distorted growth. To treat infestations, rinse the plant with water or use insecticidal soap.

Diseases

Root rot: Overwatering is a common issue that leads to root rot. Ensure the pot has good drainage and the soil does not remain soggy. Let the top inch of soil dry out between waterings.

Fungal Diseases: High humidity without proper air circulation can lead to fungal diseases. Make sure the plant is in a well-ventilated area, and reduce humidity if you notice fungal growth.

Common Problems

Brown Leaf Tips: This can be caused by low humidity, over-fertilization, or exposure to chemicals in tap water. Increase humidity around the plant and use rainwater or distilled water for watering if possible. Fertilize sparingly.

Yellowing Leaves: Overwatering, poor drainage, or a lack of nutrients can cause leaves to turn yellow. Adjust watering practices and consider repotting the fern in fresh potting mix if drainage is poor.

Leggy Growth: Insufficient light can cause the Button Fern to stretch towards the light source, leading to leggy growth. Move the plant to a brighter location with indirect light.