Astelia nervosa
Astelia nervosa, commonly known as Mountain Astelia or Bush Astelia, is a distinctive evergreen perennial native to New Zealand's mountain regions. Known in te reo Māori as kākaha, it forms striking basal rosettes of long, sword‑shaped leaves with a silvery sheen, creating bold architectural accents for cool, moist gardens. For planting combinations and habitats, explore our alpine plants of New Zealand and native ferns.
Image credit: Mountain Astelia (Astelia nervosa) – Photo by Wikipedia contributors, via Wikipedia.
Mountain astelia forms dense basal rosettes of long, sword‑shaped leaves with a distinct silver sheen caused by fine surface hairs. Leaves arch gracefully and can reach close to a metre in ideal conditions, creating a bold architectural silhouette. Small, often hidden flowers are followed by decorative orange‑red berries held low in the foliage. Clumps expand slowly, remaining tidy and textural year‑round in shaded, moisture‑retentive sites.
In the wild, Astelia nervosa inhabits cool mountain forests, damp sub‑alpine scrub, and shaded gullies where humus‑rich soils and consistent atmospheric moisture prevail. It commonly grows beneath tall canopy species and along sheltered stream margins. Good drainage is crucial; plants are rarely found where water stagnates. These habitats provide filtered light, stable temperatures, and reliable moisture that inform successful garden cultivation.
The dense leaf rosettes intercept rainfall and leaf litter, contributing organic matter to the forest floor while creating humid micro‑pockets used by invertebrates and bryophytes. Berries provide occasional seasonal food for birds, assisting local dispersal. Clumps stabilise surface soils on banks and help slow overland flow after heavy rain, subtly enhancing moisture retention in shaded, montane ecosystems.
As a mid‑storey understorey accent, mountain astelia adds structural diversity to forest edges and sub‑alpine vegetation. Its persistent foliage offers year‑round shelter for small fauna, while the slow accumulation of organic debris beneath clumps fosters a living mulch layer. These functions are valuable in restoration plantings aiming to recreate stable, moisture‑holding understories.
Use mountain astelia as a focal specimen in shaded courtyards, mass‑plant it for dramatic texture beneath trees, or combine it with ferns, renga renga lily, and shade‑tolerant grasses for layered compositions. In containers, its metallic foliage pairs well with dark pots and restrained palettes. It excels in modern, minimalist plantings where strong form and leaf effects are prized.
Provide humus‑rich, free‑draining soil, partial shade, and steady moisture without saturation. Mulch annually to maintain cool roots and improve soil structure. Shelter from hot, drying winds preserves the silver leaf finish. In very cold sites, ensure excess winter water can drain away to prevent crown damage. Slow‑release, balanced fertiliser in spring supports steady growth.
Plant in autumn or early spring. Dig a wide hole and incorporate composted organic matter; set the crown level with the surrounding soil. Water in thoroughly to settle fines around roots and apply a thin mulch, keeping it clear of the crown. Space plants 60–90 cm apart for overlapping foliage and an interlocking, weed‑suppressing canopy in a season or two.
Best performance occurs where morning light meets afternoon shade, such as the east side of buildings or beneath high canopies. Avoid reflected heat from paving in summer. Soils should be friable with ample organic content; in heavy ground, raise beds or amend generously with fine bark and leaf mould to enhance porosity and oxygen around roots.
Remove spent or winter‑marked leaves cleanly at the base to maintain a crisp outline. Top‑up mulch annually and water during extended dry periods. Container plants appreciate monthly deep watering in summer and a spring feed with a slow‑release fertiliser formulated for foliage plants. Divide congested clumps in spring only when necessary to preserve mature character.
Astelia nervosa is not currently threatened but benefits from protection of cool, shaded forest margins and montane gullies. Prevent stock access in restoration areas, maintain canopy cover, and manage invasive weeds that alter understorey moisture. Garden cultivation can complement in‑situ conservation by showcasing and valuing this distinctive native form.
| Scientific Name | Astelia nervosa |
|---|---|
| Height | 60–90 cm |
| Spread | 60–100 cm |
| Water Needs | Moderate; keep evenly moist |
| Light | Partial shade to bright shade |
| Frost Tolerance | High; very hardy |
| Salt Tolerance | Low |
| Growth Rate | Slow to moderate |
| Lifespan | Long‑lived perennial |
Best in cool, temperate climates with consistent moisture and shelter from hot, drying winds.
| 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 | Moderate |
| Invercargill | Moderate |
Moist, free‑draining, humus‑rich soils; avoid waterlogging.
Thrives in partial shade; tolerates bright shade.
Keep evenly moist, especially during establishment and dry spells.
Use mountain astelia as a bold architectural accent in shaded borders, contemporary courtyards, and large containers. Its metallic foliage provides year‑round structure, contrasts beautifully with fine fern textures, and anchors compositions where flowers are secondary to strong form and leaf effects.
Divide crowded clumps; refresh mulch.
Maintain moisture in heat; provide shade in extremes.
Top‑dress with compost; remove tired foliage.
Minimal care; protect from pooling water.
Remove damaged or spent leaves at the base as needed. Trim old or tattered foliage close to the crown to keep the rosette tidy, and avoid cutting into the central growth point. Hard pruning is unnecessary; seasonal grooming maintains appearance.
Plant at the original depth into free‑draining, humus‑rich soil. Water in thoroughly to settle roots, then apply an organic mulch to conserve moisture and suppress weeds. Space plants to allow mature rosettes to expand without crowding.
Divide established clumps in spring by gently separating offsets with a sharp, clean knife, ensuring each division retains healthy roots. Seed is viable but slow and variable; surface‑sow fresh seed and keep evenly moist until germination.
Known to Māori as kākaha, this species has long been used for practical and aesthetic purposes. The tough, fibrous leaves were selected for weaving and binding, while the plant’s striking form made it a valued feature around kāinga and cultivated spaces. Today it continues to be appreciated in contemporary gardens that reference indigenous plantings and materials.
Generally trouble‑free in suitable conditions. Avoid waterlogging to prevent crown and root issues, and monitor for snails or slugs that may chew tender new growth. Provide airflow and remove debris to minimise fungal problems.
Use a dark, organic mulch to accentuate the silver foliage, conserve soil moisture, suppress weeds, and buffer temperature swings. Refresh the layer annually and keep mulch clear of the central crown to prevent rot.