Armstrong's Speargrass

Aciphylla montana

Not Threatened

The Armstrong's Speargrass (scientific name: Aciphylla montana), often also called the Mountain Spaniard, is a quintessential alpine perennial herb endemic to the South Island of New Zealand. Forming dense, spiny rosettes, this member of the Apiaceae family is a master of survival in the high-rainfall tussock grasslands and herbfields of the central Southern Alps. From Mt Hutt to Mt Cardrona, its architectural presence adds a unique texture to the mountain landscape, standing as a testament to the evolutionary ingenuity of New Zealand's high-country flora.

Armstrong's Speargrass (Aciphylla montana) showing its spiny rosette habit — Image credit: Armstrong's Speargrass (*Aciphylla montana*) - photo by Wikipedia contributors, via Wikipedia

Plant Description

Identification and Physical Characteristics

Aciphylla montana forms attractive, often quite large rosettes that can reach up to 250 mm in diameter. The leaves are remarkably rigid and leathery, a key adaptation to the wind-swept alpine environment. Each leaf is pinnately divided into several pairs of narrow, sharp-tipped segments, typically growing up to 30 cm long in the primary variety. The coloration is generally a bright, healthy green. When flowering, the plant produces a central stalk that rises impressively above the foliage, sometimes reaching heights of 60 cm. These stalks bear dense umbels of small, cream-coloured flowers, which are shielded by rigid, spiny bracts that effectively discourage herbivores.

Quick Facts

*Aciphylla montana* quick facts
Scientific Name	Aciphylla montana
Height	0.4 - 0.6 metres (when flowering)
Spread	0.2 - 0.3 metres
Water Needs	Moderate; prefers consistent alpine moisture
Light	Full sun - requires bright mountain light
Frost Tolerance	High - adapted to severe alpine winters
Salt Tolerance	Low
Growth Rate	Slow
Lifespan	Perennial

Climate Best Suited to

Armstrong's Speargrass is a specialist of the cool, moist, and high-light environments of the South Island Alps. It thrives in regions with cold, snow-covered winters and relatively dry, cool summers. It is not well-suited to the humidity and persistent warmth of northern New Zealand lowland climates, where it would likely succumb to rot or general environmental stress. It requires a climate that provides clear air and a high degree of seasonality.

Regional Suitability

City suitability for Armstrong's Speargrass
City	Climate Suitability
Auckland	Low (unsuitable climate)
Wellington	Medium (requires cool, well-ventilated site)
Christchurch	High (in appropriate garden settings)
Queenstown	High

Plant Habitat

Natural Occurrence and Ecology

The natural habitat of Aciphylla montana is restricted to the central southern Alps of the South Island, typically at elevations between 1200 and 2000 meters above sea level. It is a common component of tall tussock grasslands and alpine herbfields, particularly east of the Main Divide. It is often found growing in stable, well-drained, yet moisture-retentive soils, sometimes situated near rocky outcrops or on stabilized scree slopes where environmental moisture is consistently available.

Growing Requirements

Soil Requirements

Requires well-drained, moderately fertile soil. A gritty loam that provides excellent drainage while retaining some moisture at root level is ideal. It resents heavy, poorly-drained clay soils which can lead to crown rot.

Well-drained
Gritty loam
Avoid waterlogging

Light Requirements

Demands full sun. As an alpine specialist, it is adapted to high light levels and will not thrive in shady conditions. Bright, open positions are essential for the plant to maintain its compact rosette form.

Full Sun only

Water Requirements

While drought-tolerant once established, cultivated plants benefit from regular watering, especially during the active growing season. The goal is to provide consistent moisture at the root level without allowing the crown to remain wet.

Moderate
Consistent root moisture

Planting and Establishing

Establishment Guidance

Armstrong's Speargrass is best established from young plants, as mature specimens have deep taproots and do not transplant well. Plant in early spring or autumn. Ensure the planting hole is deep and incorporates plenty of drainage material. Do not bury the crown; it should sit slightly above the soil surface. Applying a thick mulch of stone chips or gravel helps protect the crown from rot and keeps the root zone cool, mimicking its natural mountain environment.

Ecological Role

Biodiversity and Ecosystem Impact

In its alpine home, Aciphylla montana provides valuable structure and resource diversity. The dense, spiny rosettes offer a protected micro-habitat for specialized alpine invertebrates and may provide shelter for smaller mountain herbs. The summer flower stalks are a key source of nectar and pollen for high-altitude flies, moths, and native bees. Furthermore, its root system contributes to the stability of mountain soils in its high-rainfall habitats.

Uses & Significance

Garden Uses

A striking addition to rock gardens, alpine troughs, and gravel gardens. Its architectural form provides a sharp contrast to softer foliage. It is a highly desirable plant for those wishing to create a representative South Island alpine display.

Rock gardens
Alpine troughs
Architectural interest

Ecological Value

Supports specialized alpine biodiversity and acts as an important resource for mountain-dwelling pollinators.

Pollinator support
Alpine habitat contributor

Landscaping Uses

Used in specialized landscape designs to evoke the ruggedness of the Southern Alps. Its compact rosettes are perfect for creating textural patterns in minimalist native plantings. It is particularly effective when used in group plantings within rocky or high-altitude developments where its slow growth and unique form can be appreciated.

Seasonal Care Calendar

Spring

Watch for new rosettes emerging. This is the best time for light fertilization and checking that the drainage remains sharp after winter rains.

Monitor growth
Light feeding

Summer

Maintain consistent moisture at the root level during dry spells. Watch for the impressive flower spikes and enjoy the alpine display.

Regular watering
Watch for flowering

Autumn

Collect mature seeds. Carefully remove any fallen debris from the center of the plant to prevent winter rot.

Seed collection
Tidy debris

Winter

The plant is dormant and extremely cold-hardy. Ensure the site is free-draining and that no heavy mulch is smothering the crown.

Maintain dormancy
Ensure drainage

When to Prune and How Much

Minimal pruning is required. Remove the spent flower stalks at the very base once they have finished and seeds have been harvested. Occasionally, trim off any individual dead or damaged leaves at the base of the rosette to maintain a neat and healthy appearance.

Remove spent flower stalks
Trim dead base leaves

Always wear gloves and use sharp, clean tools to avoid damaging the plant or yourself.

How to Grow Armstrong's Speargrass

Growing Armstrong's Speargrass (Aciphylla montana) from seed or division is a rewarding challenge for the dedicated native plant enthusiast. This species, like many of its alpine relatives, requires precise conditions to ensure successful germination and healthy long-term growth. Because it is highly adapted to the high-altitude environments of the South Island, the most critical factors are providing absolute full sun, excellent air movement, and a substrate that provides rapid drainage while still allowing the roots to access consistent moisture. Outside of its natural alpine range, it is often easier to manage in specialized containers or alpine houses where its environment can be carefully monitored.

From Seed

Propagation from seed is the most reliable method for Aciphylla montana. Collect seeds in late summer when the flower umbels have turned dry and brown. Fresh seed should be used for the best results. Sow the seeds onto the surface of a very gritty seed-raising mix-a blend of fine gravel, pumice, and sterilized potting soil is often effective. Lightly cover with a thin layer of fine grit. The seeds require a period of cold stratification to break their natural dormancy. In colder climates, leaving the trays outdoors in a sheltered spot over winter provides this naturally. In warmer regions, a 6-8 week period in a refrigerator may be necessary before moving them to a cool, bright spot for germination. Germination can be slow and sporadic, often taking several months.

Collect fresh seeds in autumn
Sow on gritty, sterile mix
Provide cold stratification
Maintain moisture

Once seedlings are large enough to handle, move them into individual deep pots to accommodate their developing taproots.

From Cuttings / Division

Vegetative propagation via division is possible but carries a high degree of risk. Mature plants have a sensitive taproot system that resents being disturbed. If division is attempted, it should be done in early spring as new growth begins. Carefully lift the clump and use a sharp, sterilized knife to separate individual rosettes, ensuring each piece has a good portion of the root system attached.

Replant the divisions immediately into a gritty mix and maintain consistent moisture until established. This method is generally less successful than growing from seed.

Divide in early spring
Use clean, sharp tools
Replant immediately

Additional Methods

Because the plant is so difficult to transplant once mature, the best "additional method" is meticulous site selection and preparation. Creating a dedicated rockery or trough with a deep layer of drainage material at the bottom ensures that the roots can remain cool while the surface drainage stays sharp. Using a deep mulch of stone chips or fine gravel around the base of the plant is vital; it protects the crown from excess moisture, keeps the roots cool, and beautifully mimics the plant's natural mineral-rich mountain habitat.

Select bright, airy position
Use deep stone mulch
Avoid root disturbance

Pests & Diseases

Armstrong's Speargrass is generally resistant to many common pests. However, in lowland settings, it can be susceptible to aphids on the new growth and root or crown rot if the soil is too heavy or poorly drained. Slugs and snails may be a problem for young seedlings. Maintain sharp drainage and a bright, airy position to prevent these problems.

Cultural Significance

Speargrasses, known to Māori as Taramea, have a significant place in New Zealand's cultural and botanical heritage. While Aciphylla montana is a specialized alpine species, it is part of this broader lineage of unique and resilient plants that characterize the high country of Aotearoa. It is highly valued by botanists and alpine collectors for its distinctive form and its role in New Zealand's unique mountain biodiversity.

High-country botanical heritage
Alpine biodiversity specialist

Bonus Tip

When growing in pots, use a terracotta container to help keep the roots cool and allow for better aeration of the gritty soil mix.

Cultivating this species effectively involves a deep understanding of its natural adaptations and environmental preferences. By mimicking its native habitat-whether that be the cool, moist understory of a temperate rainforest or the exposed, well-drained slopes of an alpine range-gardeners can ensure robust growth and long-term health. Regular observation and minimal, targeted intervention are often the best strategies for maintaining the unique characteristics and ecological contributions of this remarkable New Zealand native plant.

Plant Conservation

Conservation Status and Threats

Currently classified as "Not Threatened," Aciphylla montana has healthy populations across its central southern Alps range. However, it remains vulnerable to the long-term impacts of climate change and the continued presence of introduced browsing animals like hares and chamois. Protecting New Zealand's alpine herbfields is vital for ensuring the continued survival of this and many other specialized native species.