<i>Blechnum procerum</i>(Blechnum procerum) hero image

Crested Hard Fern

Blechnum procerum

Not specified

This native plant, known as Crested Hard Fern(scientific name: Blechnum procerum), is a remarkable species endemic to New Zealand. It is characterized by its unique features, ecological role, and cultural significance. This comprehensive guide provides detailed information on its care, propagation, and importance within the New Zealand ecosystem. Understanding this plant contributes to the appreciation of our rich biodiversity and heritage, and supports conservation efforts for Browse All.

<i>Blechnum procerum</i>(Blechnum procerum) showing <i>Blechnum procerum</i>growth habit
Image credit: Crested Hard Fern (Blechnum procerum) - Photo via Wikipedia

Plant Description

Identification and Physical Characteristics

Blechnum procerum, commonly known as Crested Hard Fern or Small Kiokio, is a small to medium-sized native fern of New Zealand. It is characterized by its dark green, leathery fronds that grow in a compact, often crested, rosette. This fern is typically found in damp, shady areas of forests, along stream banks, and on rocky outcrops. Its fronds are dimorphic, with sterile fronds that are broad and leafy, and fertile fronds that are narrower and more upright. New fronds often emerge with a bronzish or reddish hue before maturing to dark green.

Quick Facts

Blechnum procerum quick facts
Scientific Name Blechnum procerum
Height 20-50 cm
Spread 30-60 cm
Water Needs Moderate to high; prefers consistently moist soil
Light Partial to full shade
Frost Tolerance Moderate
Salt Tolerance Low
Growth Rate Slow
Lifespan Perennial

Climate Best Suited to

Blechnum procerumis well adapted to various New Zealand regions.

Regional Suitability

City suitability for Blechnum procerum
City Climate Suitability
Auckland High
Wellington High
Christchurch Medium

Plant Habitat

Natural Occurrence and Ecology

Blechnum procerum, also known as Crested Hard Fern or Small Kiokio, is a widespread fern species predominantly found throughout New Zealand, including the North Island, South Island, Stewart Island, Chatham Islands, and several subantarctic islands (Antipodes, Auckland, and Campbell Islands).This fern occupies a wide altitudinal range, from lowland areas near sea level up to montane and subalpine zones, reaching elevations of 1200 meters on Mt Ruapehu and up to 1375 meters on Mt Peel in north-west Nelson. It is less common below 300 meters in the North Island.Blechnum procerumthrives in diverse habitats, including:Forests:Open kauri, podocarp, broadleaved, and beech forests, as well as under mānuka and kānuka.Open Areas:Scrub, amongPhormium, under introduced conifers, subalpine scrub, and tussock grassland. It can also be found in swamp forests.Specific Microhabitats:It grows on the forest floor, streambanks, in gullies, along tracksides, at forest margins, in open rocky areas, on roadside banks and cuttings, in ditches, on swampy ground, on pākihi soils, and in rough pasture.The fern prefers damp, shady conditions with consistently moist, well-drained, humus-rich soil, and a mild, humid climate. While it generally favours shade, it can also tolerate open aspects and a range of moisture regimes.

Growing Requirements

Soil Requirements

Prefers well-draining soil rich in organic matter.

  • Well-drained
  • Loamy

Light Requirements

Grows best in partial to full sun.

  • Full Sun
  • Partial Shade

Water Requirements

Requires regular watering during dry periods.

  • Regular
  • Drought tolerant once established

Planting and Establishing

Establishment Guidance

Plant Blechnum procerumin a hole twice the width of the root ball.

Proper establishment is key to long-term success. Ensure the planting hole is twice as wide as the root ball and backfill with a mix of native soil and organic compost. Initial watering should be thorough, followed by regular monitoring during the first two growing seasons to ensure the plant becomes well-anchored and resilient to local climate fluctuations.

Ecological Role

Biodiversity and Ecosystem Impact

Provides habitat and food for native fauna.

This species plays a vital role in its local ecosystem, providing essential habitat and food sources for native biodiversity. Its presence supports complex ecological interactions, contributing to the overall health and stability of the environment. By planting this native, you help maintain the intricate web of life that defines New Zealand's unique natural heritage.

Uses & Significance

Garden Uses

Ideal for rock gardens and native borders.

  • Rock gardens
  • Ground cover

Ecological Value

Supports local pollinators.

  • Birds
  • Insects

The versatility of this plant makes it a valuable addition to many New Zealand gardens. Beyond its aesthetic appeal, it offers practical benefits such as soil stabilization and shelter for smaller plants. Its historical and modern uses highlight its enduring importance in both traditional practices and contemporary landscape design, making it a thoughtful choice for any restoration or gardening project.

Landscaping Uses

Adds texture and form to modern landscapes.

In a landscape setting, this plant provides excellent structure and year-round interest. Its unique form and foliage can be used to create focal points or as a cohesive element in a larger native planting scheme. It pairs well with other New Zealand natives, allowing for the creation of diverse and resilient garden environments that reflect the natural beauty of Aotearoa.

Seasonal Care Calendar

Spring

Mulch and apply balanced fertilizer.

  • Fertilize
  • Mulch

Summer

Water deeply during dry spells.

  • Water
  • Check for pests

Autumn

Tidy up any dead foliage.

  • Prune lightly
  • Plant new specimens

Winter

Protect from heavy frosts if necessary.

  • Frost protection

When to Prune and How Much

Minimal pruning required to maintain shape.

  • Remove dead branches

Always use clean, sharp tools.

Regular maintenance through careful pruning ensures the plant remains healthy and maintains its desired shape. Focus on removing dead or diseased wood to promote better air circulation and prevent the spread of pathogens. Proper pruning techniques help the plant direct its energy toward new growth, resulting in a more robust and aesthetically pleasing specimen in your garden.

How to Grow Crested Hard Fern

Cultivating Blechnum procerum(Blechnum procerum) is a rewarding endeavor for any gardener interested in New Zealand's unique flora. This species can be propagated through several methods, each requiring specific conditions to ensure healthy growth and establishment. Successful propagation depends on mimicking the plant's natural environment and providing consistent care during the early stages of development.

From Seed

Propagation from seed is often the most effective way to produce a large number of Blechnum Procerum plants. Seeds should be collected when they are fully mature. Freshly collected seeds generally have higher germination rates than those that have been stored for long periods.

Sow fresh seeds in a seed-raising mix.

  1. Collect seeds
  2. Sow in trays

Keep moist until germination.

From Cuttings

For those wishing to replicate specific characteristics of a parent plant, vegetative propagation via cuttings is the preferred method. This technique ensures that the new plants are genetically identical to the source. Semi-hardwood cuttings taken during the appropriate season usually yield the best results for this species.

Take semi-hardwood cuttings in late summer.

  1. Take cuttings
  2. Use rooting hormone

Additional Methods

Depending on the growth habit of Blechnum procerum, other methods such as division or layering might also be viable options. Division is particularly suitable for plants that form dense clumps or have spreading root systems, while layering can be used for species with trailing or flexible stems.

Division can be done in early spring.

  1. Divide clumps
  2. Replant immediately

Pests & Diseases

Generally resistant to major pests.

While generally resilient, maintaining optimal growing conditions is the best defense against pests and diseases. Regular monitoring allows for early detection of any issues, which can often be managed through cultural practices or organic interventions. Ensuring good air circulation and appropriate watering will significantly reduce the plant's susceptibility to common environmental stresses and pathogens.

Cultural Significance

While not as widely documented for traditional Māori uses as some other ferns, the Crested Hard Fern (Blechnum procerum) was recognized for its presence in healthy forest ecosystems. Its fronds may have been used for weaving or other purposes, and the plant was likely used in rongoā (traditional Māori medicine) for various ailments.

  • Traditional medicine
  • Crafts

Bonus Tip

Excellent for low-maintenance gardens.

For an extra boost, consider applying a thin layer of high-quality organic mulch around the base of the plant. This helps retain soil moisture, suppresses weeds, and gradually improves soil structure as it breaks down. This simple step can make a significant difference in the plant's overall vigor and resilience, especially during periods of extreme weather.

Plant Conservation

Conservation Status

Small Kiokio (Blechnum procerum, nowParaBlechnum procerum) is a native New Zealand fern with a national conservation status of "Not Threatened." This classification reflects its relatively stable populations across its range, particularly in the South Island where it becomes more common moving southward and reaches sea level in southern regions.Despite its secure national status, small kiokio faces ongoing conservation challenges that require continued habitat protection and management. The primary threats include habitat loss and fragmentation through deforestation, land conversion for agriculture and urban development, and modifications to its natural habitats including mixed forests, subalpine scrub, and tussock grasslands. Its preference for specific altitude ranges and cooler climates makes it potentially vulnerable to climate change impacts, particularly at the edges of its distribution. Changes to forest composition and structure, including alterations to understory conditions and moisture levels, can impact local populations. Competition from invasive plant species, browsing pressure from introduced mammals, and soil disturbance from human activities also pose challenges to natural regeneration and population stability. The species' distribution across diverse habitat types from sea level to subalpine zones requires ecosystem-level conservation approaches that protect the full range of environments it occupies. Conservation efforts focus on protecting intact forest and grassland ecosystems, controlling invasive species, maintaining appropriate land management practices that preserve native understory communities, and supporting restoration projects that include native fern species. Its role as a traditional resource for Māori cultural practices makes its conservation culturally significant for maintaining connections to traditional knowledge and practices. By supporting habitat protection across its range, sustainable land management practices, and education about the importance of native understory species, we can help ensure the continued survival of this culturally and ecologically important native fern.