Necklace Fern
Asplenium flabellifolium
The Necklace Fern (scientific name: Asplenium flabellifolium), also commonly known as the Walking Fern or Butterfly Fern, is a delicate and distinctive perennial herb native to New Zealand and Australia. A member of the Aspleniaceae family, it is recognized for its long, slender, and often prostrate fronds featuring fan-shaped leaflets. It thrives in a variety of environments, from the shaded forest floor to damp rocky crevices. This comprehensive guide provides detailed information on its unique "walking" habit, care, and its specialized role within our unique native forest and coastal ecosystems. Understanding this plant contributes to the appreciation of our rich biodiversity and heritage, and supports conservation efforts for all native species.
Plant Description
Identification and Physical Characteristics
Asplenium flabellifoliumis a delicate perennial fern characterized by its long, trailing, or prostrate fronds that typically measure 10-30 cm in length. Its leaflets, or pinnae, are uniquely fan-shaped (flabellate), often deeply lobed or toothed, giving the entire frond a lacy, necklace-like appearance. A fascinating botanical feature of this species is the development of small plantlets, or bulbils, at the tips of the fronds. When these tips touch a suitable substrate, the plantlets can take root, effectively allowing the fern to "walk" across the forest floor or rocky surfaces. The stipes (stalks) are slender, dark, and often shiny, arising from a small, tufted central crown.
Quick Facts
| Scientific Name | Asplenium flabellifolium |
|---|---|
| Height | Up to 15 cm (trailing to 30 cm) |
| Spread | 30-60 cm (walking habit) |
| Water Needs | Moderate; requires consistent moisture |
| Light | Partial to full shade |
| Frost Tolerance | Moderate; hardy once established |
| Salt Tolerance | Moderate; found in coastal forests |
| Growth Rate | Slow to moderate |
| Lifespan | Perennial Fern |
Climate Best Suited to
Necklace Fern is well adapted to various New Zealand regions, particularly temperate maritime and forest environments where high humidity and oceanic influences mimic its natural forest floor origins.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Auckland | High |
| Wellington | High |
| Christchurch | Medium |
| Dunedin | Medium |
Plant Habitat
Natural Occurrence and Ecology
In its natural environment, the Necklace Fern is widespread across New Zealand, inhabiting a diverse range of ecosystems from coastal lowlands to montane forests. It has evolved to occupy specialized niches within the forest understory, where it typically grows in the dappled shade of damp gullies and stream banks. It is commonly found as a terrestrial groundcover, but its adaptable habit also allows it to thrive in rocky crevices, on stone walls, and occasionally as an epiphyte on tree trunks in highly humid conditions. Its presence in these habitats highlights its adaptation to cool, shaded microclimates where moisture is consistent and protection from intense direct sunlight is available throughout the year.
Growing Requirements
Soil Requirements
Prefers well-draining, fertile soil rich in organic humus.
- Well-drained
- High organic content
Light Requirements
Grows best in partial shade to full deep forest shade.
- Full Shade
- Partial Shade
Water Requirements
Requires regular watering; do not allow soil to dry out completely.
- Regular
- Moisture-loving
Planting and Establishing
Establishment Guidance
To successfully establish Asplenium flabellifolium, choose a position that is shaded, humid, and well-sheltered from drying winds. Dig a hole twice the width of the root ball and enrich the ground with plenty of organic compost or leaf mold before planting. Ensure the central crown is set level with the surrounding soil surface to prevent rot. Planting during the cooler, moist months of autumn or early spring is ideal, allowing the fern to anchor itself before summer. Providing a cool root run with a thick layer of organic mulch will help maintain the high soil moisture levels this delicate forest species prefers for healthy and vigorous establishment.
Ecological Role
Biodiversity and Ecosystem Impact
Necklace Fern plays a vital role in forest ecosystems by providing structural complexity to the ground layer and creating micro-habitats for various native invertebrates. Its dense, spreading habit helps protect the forest floor from soil erosion, especially on steep slopes and banks. By forming a lush carpet in damp, shaded areas, it contributes to moisture retention and the overall health of the understory environment. Its unique "walking" habit allows it to rapidly colonize suitable gaps in the forest floor, supporting the natural biodiversity and resilience of New Zealand's unique and intricate native botanical communities in both lowland and montane habitats.
Uses & Significance
Garden Uses
In a garden setting, Asplenium flabellifoliumis an excellent choice for shady native ferneries, rock gardens, or as a graceful groundcover in a cool courtyard. Its delicate, fan-shaped foliage provides a fine texture that contrasts beautifully with larger-leaved shade plants. It is highly valued for its ability to be grown in pots and hanging baskets, where its trailing fronds can elegantly cascade. Its unique "walking" habit makes it a favorite for gardeners wishing to create authentic, naturalizing forest displays that showcase the intricate beauty and specialized adaptations of New Zealand's diverse clumping and spreading fern species.
- Shady groundcover
- Rock garden crevice
- Hanging baskets
Ecological Value
Beyond its ornamental appeal, this species is important for supporting local forest biodiversity. It provides a micro-habitat for ground-dwelling fauna and supports native ecosystem health with its presence in riparian and coastal forest margins. Historically, the unique habit of the Walking Fern was observed and appreciated by Māori, where its presence indicated a healthy and moist forest environment. As a representative of the Aspleniaceae family, it is part of the important group of native ferns that represent the country's unique evolutionary history and the ongoing commitment to protecting the specialized lowland and coastal habitats where this beautiful species currently thrives.
- Invertebrate refuge
- Soil stabilization
Landscaping Uses
Modern landscaping can utilize Asplenium flabellifoliumto create naturalistic understory layers in specialized native or contemporary designs. Its architectural fronds and spreading habit make it a perfect softening element for the edges of forest paths or as a lush textural accent between large decorative rocks in a shaded garden. Designers often use it to add a sense of detail and 'wildness' to a project, where its trailing form can be highlighted. Its ability to maintain a neat habit while providing year-round structural interest makes it a reliable and decorative performer for high-impact native landscaping projects in cooler, humid regions across the country.
Seasonal Care Calendar
Spring
As new growth resumes and bulbils begin to root, ensure the soil moisture is consistent. This is the optimal time for maintenance pruning to remove any winter damage and to apply a light dressing of organic compost around the base.
- Spring pruning
- Monitor rooting
Summer
Provide regular misting or extra watering during prolonged dry spells to maintain the lushness of the foliage and prevent the plant from becoming stressed by excessive heat. Ensure the site remains well-shaded and protected from intense midday sun.
- Maintain moisture
- Provide shade
Autumn
The "walking" plantlets will continue to establish. Tidy up the area by removing any large fallen leaves that might smother the delicate trailing stems. Ensure the site remains well-drained as the weather becomes wetter to prevent any root rot.
- Tidy debris
- Check drainage
Winter
Naturally quite hardy in its native range but sensitive to severe frosts. Minimal intervention is needed during the dormant winter months; simply ensure the area stays free of heavy organic debris that could trap stagnant moisture around the base.
- Frost protection
- Clear debris
When to Prune and How Much
Asplenium flabellifoliumrequires very little pruning. Maintenance is primarily limited to removing any dead, yellowing, or winter-scorched fronds in early spring before the new growth cycle begins. This improves air circulation around the crown and reduces the risk of fungal diseases. If the fern becomes too congested in a container or along a garden border, light thinning can be done to maintain its elegant architectural form. Always use sharp, sterilized tools to ensure clean cuts and to minimize the potential for introducing infection to the sensitive central stock of this beautiful native ornamental fern.
- Remove dead fronds
- Maintenance thinning
Always use clean, sharp tools.
How to Grow Necklace Fern
Cultivating the Necklace Fern (Asplenium flabellifolium) is a rewarding endeavor for any gardener interested in New Zealand's delicate forest flora. This resilient species is most commonly and easily grown from the small plantlets (bulbils) that form on its trailing fronds. Replicating its natural well-drained, organic-rich and humid forest understory habitat is the most critical factor for ensuring long-term success and maintaining its healthy, spreading foliage in a garden setting.
From Bulbils
Propagation via bulbils is the most effective method for producing new ferns. When the tip of a mature frond produces a small plantlet with its own tiny roots, it can be gently pinned down onto the surface of a moist, organic-rich potting soil or simply allowed to root naturally where it touches the ground. Once the young fern has established its own root system and grown several new fronds, it can be carefully detached from the parent frond and moved to its permanent position. Keep the establishing plantlets in a warm, humid, and brightly lit spot out of direct sunlight until they are robust enough for the garden.
Pin down mature bulbils.
- Select healthy plantlets
- Ensure contact with moist soil
Keep moist until established.
From Cuttings
Vegetative propagation via division of mature clumps is possible and is best performed in early spring as new growth commences. Carefully lift a healthy clump and divide the central stock into smaller sections, ensuring that each new section has at least one active bud and a substantial portion of the original root system. These divisions should be replanted immediately into a moist, well-draining potting medium and kept in a cool, bright, and highly humid spot until signs of new growth are observed, indicating that they have successfully re-established themselves and are ready for the garden or a specialized container.
Division is best attempted in early spring.
- Carefully separate clumps
- Replant in moist soil
Additional Methods
Ensuring the right growing environment is often more critical than complex propagation techniques for this species. It thrives when its roots are kept cool and moist within an organic substrate, making it perfect for specialized shady rockeries or native borders. Avoid areas subject to intense midday heat or prolonged drought, which can cause the delicate fronds to scorch and decline. Once established, the fern is relatively low-maintenance, requiring only regular watering and occasional misting during dry periods to maintain its healthy architectural form and vibrant spreading habit throughout its lifespan in your garden.
Once planted, it requires very little intervention.
- Monitor soil moisture
- Maintain high humidity
Pests & Diseases
Asplenium flabellifoliumis generally resistant to most common garden pests, though it can occasionally attract slugs and snails on tender new growth. Regular monitoring and the use of non-toxic, organic controls are recommended to keep the foliage healthy. The primary risk in cultivation is root or crown rot, which occurs if the soil remains waterlogged or if drainage is poor. Occasionally, fungal leaf spot may appear during periods of high humidity, but this can be mitigated by ensuring good air circulation. Ensuring that the planting site has excellent drainage and appropriate humidity levels are the best ways to ensure the long-term health of this hardy native spreading fern.
Cultural Significance
As a specialized coastal and lowland endemic, Asplenium flabellifoliumis a valued component of New Zealand's botanical heritage. Its unique "walking" habit was historically observed and appreciated, signifying a healthy and moist forest environment. While specific traditional Māori names or uses are less widely documented than for more prominent ferns, it represents the incredible diversity and adaptation of Aotearoa's native forest flora. Today, it stands as a symbol of the unique evolutionary history of our native spleenworts and the ongoing commitment to protecting the specialized forest habitats where this beautiful Walking Fern currently thrives across the country.
- Forest heritage
- Botanical curiosity
Bonus Tip
To truly showcase the "walking" nature of the Necklace Fern, plant it in a wide, shallow pot or a large hanging basket. This allows the fronds to trail over the edges and enables you to watch as new plantlets form and attempt to "step" out into the surrounding air, providing a fascinating and dynamic miniature landscape within your garden or home.
Related Plants
Explore other native plants that share similar characteristics or habitats with Necklace Fern (Asplenium flabellifolium), offering further insights into New Zealand's diverse flora. These related species provide context and opportunities for complementary planting in your garden.
Plant Conservation
Conservation Status
Currently classified as 'Not Threatened' nationally, Asplenium flabellifolium remains a stable and common part of New Zealand's forest biodiversity. However, its continued success is linked to the preservation of its specialized lowland and coastal habitats, which can be vulnerable to land development and the spread of aggressive invasive weeds. Ensuring that these natural forest environments remain protected from excessive human disturbance is key to maintaining the healthy populations of the Necklace Fern that currently thrive across its wide natural range on both the North and South Islands.