Button Fern
Pellaea rotundifolia native plants index
Button Fern (scientific name: Pellaea rotundifolia) Button Fern is a distinctive native fern with small, round leaflets arranged along arching fronds. It grows on rocks and cliff faces, often in dry conditions, making it unique among New Zealand's ferns for its drought tolerance. Explore more in the native plants index.
Plant Description
Botanical Features
Button Fern (Pellaea rotundifolia) is a compact, evergreen fern native to New Zealand and Australia. It is characterized by its arching fronds, which can reach up to 10-18 inches (25-46 cm) in length, covered with numerous small, round, glossy, deep green leaflets (pinnae). The leaf stalks turn a dark red as the plant ages, creating an appealing visual contrast. This fern typically grows to about 6-12 inches (15-30 cm) in height and spread. Unlike many other ferns, the Button Fern is more tolerant of drier conditions and does not require the high humidity often preferred by other fern species. It thrives in well-drained, acidic to neutral soil and prefers filtered shade or indirect light. It is often found in rocky crevices, cliff sides, and moist forests in its native habitat.
Quick Facts
Overview
| Scientific Name | Pellaea rotundifolia |
|---|---|
| Height | 15-30 cm |
| Spread | 30-50 cm |
| Water Needs | Low to moderate |
| Light | Partial shade |
| Frost Tolerance | Moderate |
| Salt Tolerance | Poor |
| Growth Rate | Slow |
| Lifespan | Long-lived |
Climate Best Suited to
Regional climate suitability across major New Zealand cities.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Whangārei | Ideal |
| Auckland | Ideal |
| Hamilton | Ideal |
| Tauranga | Ideal |
| Rotorua | Ideal |
| Gisborne | Ideal |
| New Plymouth | Ideal |
| Napier | Ideal |
| Whanganui | Ideal |
| Palmerston North | Ideal |
| Wellington | Ideal |
| Nelson | Ideal |
| Christchurch | Ideal |
| Dunedin | Ideal |
| Invercargill | Ideal |
Natural Habitat
Button Fern is native to New Zealand, Australia, and Norfolk Island. In its natural habitat, it is typically found in rocky crevices and on cliff sides, as well as in scrub and moist forested areas, and occasionally in drier woodland areas. It is often found growing on limestone cliffs. Unlike many other ferns that prefer consistently moist environments, the button fern is more tolerant of drier conditions and well-draining soil.
Plant Conservation
Conservation
Pellaea rotundifolia, commonly known as the button fern, is a species of fern endemic to New Zealand. According to the 2017 assessment of the conservation status of New Zealand indigenous vascular plants, Pellaea rotundifolia is classified as "Not Threatened" under the New Zealand Threat Classification System (NZTCS). This fern is native to New Zealand, Australia, and Norfolk Island, growing in scrub and forests, often found in rocky crevices, cliff sides, and moist forested areas. It is also a popular garden and houseplant due to its compact, evergreen nature and round, dark-green, leathery pinnae. The Royal Horticultural Society has awarded it the Award of Garden Merit.
Growing Requirements
Substrate
Humus-rich, free-draining media with leaf mould and fine grit. Avoid soggy potting mixes; excellent in shallow woodland soils and containers.
Light
Bright shade to filtered light; protect from hot afternoon sun.
Moisture
Keep evenly moist; allow top layer to just dry slightly between waterings; avoid waterlogging the crown.
For Button Fern (Pellaea rotundifolia), choose a site with partial shade and soil that is low to moderate. Incorporate composted organic matter to improve structure and drainage. Plant with the crown or root collar at soil level, then apply a 5-8 cm mulch to moderate temperature, conserve moisture, and suppress weeds. Protect young plants from extremes while establishing and consider the stated frost tolerance (moderate) when siting near exposure or cold air drains.
Planting Guide
1. Light:
- Indoors: Button Ferns prefer bright, indirect light. A north-facing window or a spot with filtered light is ideal. Direct sunlight can scorch its delicate leaves. They can tolerate lower light conditions but may exhibit leggy growth.
- Outdoors: Plant in a location that receives partial shade. Too much direct sunlight can damage the leaves.
2. Soil:
- Indoors: Use a well-draining, peat-based potting mix. You can enhance drainage by mixing standard houseplant soil with perlite or vermiculite. A suitable mix can include equal parts peat, perlite, and potting soil. The ideal pH level is slightly acidic to neutral (6 to 7).
- Outdoors: Ensure the garden soil is rich, well-draining, and slightly acidic. Amending with compost or peat moss can help achieve the right conditions.
3. Water:
- Keep the soil consistently moist but not waterlogged. Water when the top inch of soil feels dry to the touch.
- Button Ferns are sensitive to chlorine and salts in tap water, so using rainwater or distilled water is preferable.
- Ensure the pot has good drainage, and always empty the saucer after watering to prevent root rot. Yellowing leaves can indicate overwatering.
4. Humidity:
- As a tropical plant, it enjoys high humidity. Moderate to high humidity (around 40-50%) is ideal.
- You can increase humidity by placing the pot on a tray filled with pebbles and water, misting the plant regularly, or using a humidifier. Bathrooms can be good locations due to naturally higher humidity.
5. 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, as sudden temperature changes can stress the plant. It is not frost-tolerant and should be brought indoors if temperatures drop below 50°F (10°C).
Ecological Role
Button fern (Pellaea rotundifolia) is a drought-tolerant fern of rocky outcrops and bush margins, contributing ground cover, litter, and habitat in dry shade.
Habitat Functions
- Soil holding: Rhizomes and fibrous roots bind shallow, rocky soils on banks and ledges.
- Refuge: Low fronds shelter invertebrates and protect seedling microsites from desiccation.
Trophic Links
- Litter inputs: Evergreen fronds contribute persistent organic matter, supporting decomposer communities.
- Spore production: Spores feed specialised microfauna and enable recolonisation after disturbance.
By armouring thin soils and moderating the forest floor, button fern supports resilience in dry, shaded habitats.
Uses & Significance
Practical Applications
Beloved indoor/outdoor container fern with distinctive round pinnae; excellent groundcover in shaded native gardens. Fronds are ideal for compact spaces and shaded courtyards.
Propagate Button Fern by division of established clumps in cool, moist conditions or by spores raised in sterile medium with bottom heat. Keep humidity high and air movement gentle to limit fungal issues while young fronds harden.
Landscaping & Design
Pellaea rotundifolia emerges as an exceptional design element for contemporary New Zealand landscapes, offering unique textural qualities that distinguish it from traditional fern applications. This endemic button fern provides distinctive architectural interest through its unusual round leaflets and compact growth habit, making it invaluable for specialized garden situations where conventional ferns may appear too delicate or overwhelming for the design intent.
Rock Garden Specialization
- Crevice garden excellence: Natural adaptation to rocky environments makes it perfect for establishing in stone walls, between pavers, and in rock garden crevices where its compact form and distinctive round foliage create striking textural contrasts against hard surfaces.
- Drought-tolerant fern option: Exceptional tolerance for dry conditions among New Zealand ferns enables successful cultivation in challenging rock garden environments where most other fern species would struggle to establish or survive.
- Alpine garden integration: Compact size and hardy nature make it ideal for alpine-style gardens where it provides soft textural relief among sturdy alpine plants while maintaining scale appropriate to smaller garden spaces.
- Scree garden applications: Ability to thrive in well-drained, rocky soils makes it valuable for scree gardens where it adds unique foliar interest while complementing drought-adapted native plant collections.
Stumpery and Woodland Gardens
- Stumpery garden enhancement: Distinctive round leaflets provide striking textural contrast in humus-rich stumperies, where it complements other ferns by bringing out individual beauty while contributing to overall woodland atmosphere.
- Understory ground cover: Low-growing habit makes it perfect for underplanting trees and shrubs, creating naturalistic woodland floor effects that soften hard edges and provide continuous green coverage in shaded areas.
- Textural diversity provider: Unique button-like leaflets offer remarkable contrast to traditional fern forms, creating visual interest and preventing monotonous appearances in fern garden collections.
- Companion fern synergy: Pairs beautifully with other New Zealand natives like Asplenium bulbiferum (Hen and Chicken Fern), creating layered effects that showcase the diverse forms within New Zealand's native fern flora.
Contemporary Garden Design
- Modernist landscape integration: Clean, geometric appearance of round leaflets aligns perfectly with contemporary design principles, providing organic softness while maintaining architectural clarity in modern landscapes.
- Container garden applications: Compact size and attractive form make it excellent for container plantings, where it can be featured as standalone specimens or combined with other native plants for mixed displays.
- Border and edge definition: Low growth habit and distinctive foliage make it ideal for edging pathways, defining garden beds, and creating formal or informal borders that maintain visual interest throughout seasons.
- Minimalist garden solutions: Understated elegance and low-maintenance requirements fit perfectly with minimalist garden designs where each plant must justify its presence through exceptional form or function.
Challenging Site Solutions
- Dry shade specialist: Unusual tolerance for dry shade conditions among ferns makes it invaluable for challenging locations under established trees or in rain shadow areas where few other plants will establish successfully.
- Coastal environment adaptation: Natural resilience to coastal conditions enables successful cultivation in seaside gardens where salt exposure and wind stress limit plant choices for shaded areas.
- Urban environment tolerance: Hardy nature and adaptability to varying conditions make it excellent for urban gardens where environmental stresses and limited maintenance access require particularly resilient plant selections.
- Heavy shade performance: Ability to tolerate heavy shade conditions provides planting solutions for deeply shaded areas where limited light prevents successful establishment of most other decorative plants.
Native Garden Integration
- Endemic authenticity: True New Zealand native status provides authentic local character in native plant gardens, supporting conservation goals while demonstrating the unique diversity of indigenous fern species.
- Ecological garden connectivity: Natural habitat preferences align with other native species, creating ecological planting associations that support native fauna while providing educational opportunities about indigenous plant communities.
- Ground cover diversity: Complements other New Zealand native ground covers like Muehlenbeckia axillaris (Creeping Pohuehue) and Leptinella squalida (Button Daisy), creating varied textural layers in native garden designs.
- Conservation landscape value: Cultivation in gardens contributes to preservation of genetic diversity while demonstrating the horticultural potential of New Zealand's unique endemic flora.
Specialty Garden Applications
- Cottage garden charm: Distinctive appearance and manageable size make it perfect for informal cottage-style gardens where it provides textural interest without overwhelming neighboring plantings or demanding excessive maintenance.
- Foliage-focused displays: Exceptional leaf form makes it valuable in foliage gardens where varied textures, shapes, and green tones create visual interest without reliance on flowering displays.
- Indoor-outdoor transition: Proven performance as houseplant combined with outdoor hardiness enables seamless design transitions between interior and exterior spaces using consistent plant materials.
- Therapeutic garden inclusion: Low-maintenance requirements and tactile interest from distinctive round leaflets make it suitable for therapeutic or sensory gardens where plant interaction enhances wellbeing.
Design Implementation Guidelines
- Placement optimization: Position in partial to full shade with morning sun exposure for optimal growth, ensuring well-drained soil conditions while maintaining consistent moisture availability during establishment.
- Spacing considerations: Allow 30-40cm spacing for individual specimens to accommodate mature spread, or plant more densely for quick ground cover establishment in appropriate situations.
- Companion plant selection: Pair with other drought-tolerant natives or shade plants that share similar cultural requirements, avoiding aggressive spreaders that might overwhelm its compact growth form.
- Seasonal maintenance planning: Minimal intervention required once established, with occasional removal of old fronds and light fertilizer application during growing season for optimal appearance.
Through its unique combination of distinctive form, environmental adaptability, and authentic New Zealand heritage, P. rotundifolia provides landscape designers with an irreplaceable native solution for specialized garden situations requiring exceptional textural interest and reliable performance.
Seasonal Care Calendar
Spring
Repot/divide overcrowded clumps; refresh mix.
Summer
Increase watering in heat; maintain humidity.
Autumn
Reduce watering as growth slows; tidy fronds.
Winter
Water sparingly; avoid cold, soggy conditions.
Pruning & Maintenance
Techniques and Timing
Remove old, discoloured fronds at the base to encourage fresh growth.
Prune Button Fern lightly to maintain structure; remove damaged shoots and avoid hard cuts on older wood.
How to Grow Button Fern
Button Fern is a distinctive native New Zealand fern with small, round leaflets arranged along arching fronds. It grows on rocks and cliff faces, often in dry conditions, making it unique among New Zealand's ferns for its drought tolerance. This charming fern is highly valued for its delicate beauty and its ability to thrive in cool, moist environments. Understanding its propagation methods is key to successfully growing this delightful species.
From Division
Division of established clumps is the easiest and most reliable method for propagating Button Fern, particularly for home gardeners. This is best done in spring or autumn. Carefully dig up a mature clump and gently separate it into smaller sections, ensuring each section has a healthy portion of roots and some fronds. Replant the divisions immediately into prepared soil that is moist, well-drained, and humus-rich. Water thoroughly and keep consistently moist until new growth appears. This method is excellent for quickly expanding your stock of plants and for rejuvenating older, less vigorous clumps.
From Spores
Propagating Button Fern from spores is a rewarding method for those with patience, as it mimics the fern's natural reproductive cycle. Collect mature spores from the undersides of fronds in late summer or autumn. Sow spores on a sterile, moist substrate (e.g., peat and sand mix) in a sealed container to maintain high humidity. Keep in a warm, humid, and shaded location. Germination can take several months, forming a green film (prothalli). Once prothalli develop, transfer to a larger container and allow sporophytes to grow. Transplant young ferns once they are large enough to handle. This method allows for the production of many new plants and is ideal for large-scale restoration projects.
Pests & Diseases
Pellaea rotundifolia demonstrates exceptional resilience compared to most fern species, with its natural adaptation to rocky, dry environments providing inherent resistance to many common problems that plague moisture-loving ferns. However, understanding potential pest and disease challenges enables proactive management that ensures optimal health and appearance, particularly when transitioning between indoor and outdoor growing environments.
Common Pest Challenges
- Spider mite infestations: These microscopic pests thrive in dry conditions and can cause leaves to develop speckled, dull appearances with fine webbing visible between fronds. Most problematic in heated indoor environments or during extended dry periods outdoors.
- Mealybug colonization: White, cottony insects that cluster in frond joints and undersides, feeding on plant juices and weakening overall vigor. More common in indoor environments where natural predators are absent and conditions favor rapid reproduction.
- Scale insect attachment: Hard or soft-bodied insects that adhere to stems and leaflets, causing yellowing, stunted growth, and general decline through persistent sap feeding over extended periods.
- Aphid population establishment: Small, soft-bodied insects that cluster on new growth and frond undersides, causing distorted development and honeydew production that can lead to secondary sooty mold issues.
Environmental Stress Factors
- Overwatering damage: Despite drought tolerance, excessive moisture leads to root rot, yellowing fronds, and fungal disease development. More susceptible during cooler months when growth slows and water uptake decreases significantly.
- Humidity-related problems: Both excessive humidity without air circulation and extremely low humidity can create stress conditions that manifest as brown leaf tips, edge burning, or increased susceptibility to fungal diseases.
- Temperature stress responses: Exposure to temperatures above 24°C (75°F) can cause brown leaf tip development, while sudden temperature fluctuations stress plants and increase vulnerability to pest infestations.
- Light exposure issues: Insufficient light causes leggy growth and weakened constitution, while excessive direct sunlight burns delicate fronds and creates stress that attracts pest problems.
Disease Prevention and Management
- Fungal disease prevention: Ensure adequate air circulation around plants while maintaining appropriate humidity levels. Remove spent fronds promptly to prevent fungal spore development and spread to healthy plant material.
- Root rot mitigation: Plant in well-draining soil mixtures and avoid chronic waterlogging. Monitor soil moisture levels regularly and adjust watering frequency based on seasonal growth patterns and environmental conditions.
- Cultural disease resistance: Maintain optimal growing conditions including proper light levels, appropriate soil moisture, and good air circulation to support natural disease resistance and plant vigor.
- Sanitation practices: Remove dead, damaged, or yellowing fronds immediately to prevent pathogen establishment and maintain overall plant health and appearance throughout growing seasons.
Integrated Pest Management
- Early detection protocols: Conduct regular inspections of frond undersides, crown areas, and soil surfaces to identify pest problems before populations become established and cause significant damage.
- Biological control methods: Encourage beneficial insects in outdoor settings and consider introducing predatory mites or other natural enemies for persistent indoor pest problems when chemical controls are undesirable.
- Mechanical removal techniques: Use cotton swabs dipped in rubbing alcohol to remove mealybugs and scale insects, or spray off aphids and spider mites with strong water streams before populations become entrenched.
- Targeted treatment applications: Apply insecticidal soap or neem oil treatments for serious infestations, focusing on affected areas while avoiding excessive application that might stress already compromised plants.
Environmental Optimization
- Humidity management: Maintain moderate humidity levels around 40-60% through grouping plants, using humidity trays, or installing humidifiers while ensuring adequate air movement prevents stagnant conditions.
- Watering precision: Water thoroughly but infrequently, allowing soil to dry slightly between applications. Use rainwater or distilled water when possible to avoid chemical buildup that can stress plants over time.
- Light condition optimization: Provide bright, indirect light that supports healthy growth without causing stress. Gradually acclimate plants when moving between different light environments to prevent shock.
- Temperature stability: Maintain consistent temperatures between 18-22°C (65-72°F) while avoiding drafts, heating vents, and other sources of rapid temperature fluctuation that weaken plant defenses.
Seasonal Care Considerations
- Winter protection measures: Reduce watering frequency during dormant periods while maintaining adequate humidity. Monitor for pest activity that often increases in heated indoor environments during colder months.
- Spring monitoring intensity: Increase inspection frequency as growth resumes and pest activity intensifies. Address any problems that developed during winter dormancy before active growing season begins.
- Summer stress management: Provide additional humidity and protection from excessive heat while monitoring for drought stress indicators even though this species tolerates dry conditions better than most ferns.
- Autumn preparation activities: Gradually reduce feeding and watering as growth slows, while ensuring plants enter dormancy in optimal health to resist winter pest and disease pressures.
Recovery and Rehabilitation
- Post-treatment care: Following pest control treatments, provide optimal growing conditions to support recovery while monitoring for treatment effectiveness and potential plant stress from intervention methods.
- Gradual rehabilitation: Allow stressed or damaged plants time to recover by maintaining consistent care without additional stresses like repotting or fertilizing until new growth indicates plant recovery.
- Preventive maintenance: Establish regular care routines that support plant health and early problem detection, reducing likelihood of serious pest or disease establishment through proactive management.
- Long-term resilience building: Focus on optimal cultural conditions that support natural plant defenses rather than relying heavily on chemical interventions for sustainable long-term plant health.
Through understanding and addressing these potential challenges proactively, P. rotundifolia can maintain exceptional health and appearance while demonstrating the remarkable resilience that makes it superior to more temperamental fern species.
Cultural Significance
Cultural Importance
Houseplant and Heritage
Button fern is a classic indoor and shaded-courtyard plant, celebrated for its neat, beaded fronds. Featuring it in native plant displays connects everyday horticulture with New Zealand’s fern-rich identity.
Pellaea rotundifolia, commonly known as the Button Fern, holds cultural significance primarily among the Māori people of New Zealand. Traditionally, the Māori utilized this fern in their weaving practices and as a food source during periods of scarcity. Native to New Zealand, Australia, and Norfolk Island, the Button Fern is also widely cultivated as a houseplant due to its charming appearance and adaptability. Its small, round leaflets and cascading growth habit make it a popular choice for adding greenery to homes and gardens.
Bonus Tip
Button fern (Pellaea rotundifolia) prefers lime-free mixes. If fronds yellow between the veins, check for hidden lime in potting media or hard irrigation water. Repot into an acidic, gritty blend and water with rainwater to restore the deep, glossy green.
