Bush Flax

Basic Information

Common Name: Bush Flax
Scientific Name: Astelia banksii
Native Habitat: Native to the northern parts of the North Island of New Zealand and surrounding offshore islands. It is found primarily in coastal areas, rocky outcrops, forest margins, and can grow both terrestrially on the ground or epiphytically on tree trunks and rocks.

History / Discovery / Cultivator

The genus Astelia encompasses a fascinating group of tufted, rhizomatous plants found across the Southern Hemisphere, including New Zealand, Australia, the Pacific Islands, and South America. Astelia banksii, commonly known as Bush Flax, is a significant species within this genus, endemic to the northern regions of New Zealand. Its discovery and inclusion in the scientific record are intertwined with the broader botanical exploration of New Zealand flora that began in earnest with the arrival of European explorers and botanists in the late 18th and early 19th centuries.

While specific records pinpointing the exact moment and individual who ‘discovered’ Astelia banksii for Western science can be elusive, the plant was likely observed and cataloged by botanists accompanying early voyages of exploration, such as those led by Captain James Cook. Sir Joseph Banks, a prominent botanist who sailed with Cook on his first voyage, is commemorated in the scientific name banksii, though the formal description may have been made later based on specimens collected during these expeditions or subsequent visits. The classification and description of New Zealand’s unique flora were ongoing efforts by botanists like Joseph Dalton Hooker, who published extensively on the subject in the mid-19th century.

Long before scientific classification, Astelia banksii, like other native plants, was known and utilised by the indigenous Māori people of New Zealand. While other members of the Astelia genus, such as Astelia grandis, were particularly valued for their tough leaves used in weaving (though not as strong or fine as harakeke/true flax, Phormium tenax), Astelia banksii also likely held ecological or practical significance within Māori communities inhabiting the coastal areas where it grows. Its fibrous leaves, though perhaps less suitable for fine weaving than Phormium, could have been used for coarser cordage or other purposes.

In modern times, Astelia banksii has gained popularity as an ornamental plant, valued for its architectural form, attractive foliage – typically silvery-green, but sometimes bronze or variegated in selected cultivars – and its resilience, particularly in coastal or challenging garden environments. It is increasingly cultivated in New Zealand and internationally, often featured in landscape designs that aim to evoke a native, coastal, or contemporary aesthetic. Specialist nurseries and plant breeders have contributed to its cultivation by propagating desirable forms and making them available to gardeners. While not as widely known globally as some other New Zealand natives, its unique texture and hardiness are seeing it gain recognition among plant enthusiasts and landscape professionals. Its ability to thrive in a variety of conditions, from exposed coastal sites to sheltered garden beds, and its striking visual appeal contribute to its growing presence in horticulture, moving it from a purely wild species to a cultivated garden favourite. The journey of Astelia banksii from the rugged New Zealand coastline to gardens reflects the ongoing appreciation for the unique biodiversity of the region and the efforts of botanists, horticulturalists, and indigenous knowledge keepers over centuries.

Plant Care Summary

Botanical Insights

Adaptations

Astelia banksii exhibits several key adaptations that allow it to thrive in its native coastal and forest edge environments. One significant adaptation is its tolerance to salt spray and wind, common conditions in coastal habitats. Its tough, leathery, strap-like leaves are resilient against strong winds, and their surface structure may help shed salt. The plant’s ability to grow both terrestrially and epiphytically demonstrates remarkable adaptability, allowing it to colonize diverse niches, from the ground to tree trunks or rocky cliffs. The dense, clumping growth habit provides stability against wind and helps retain moisture and organic matter around the root system. The silvery or bronze coloration of the leaves in some forms may also offer protection against intense sunlight.

Propagation Methods

The most common and effective method for propagating Astelia banksii is by division. Mature clumps can be carefully dug up, and the rhizomatous root system can be divided into smaller sections, ensuring each section has a healthy amount of roots and foliage. This is best done in spring or early autumn. These divisions can then be replanted directly into suitable soil. Propagation by seed is also possible but is a slower process. Seeds are typically collected from the fruit, cleaned, and sown onto a well-drained seed mix. Germination can be variable, and seedlings will take several years to reach a significant size.

Toxicology

Based on available information from horticultural and botanical sources, Astelia banksii is generally considered non-toxic to humans and common household pets such as cats and dogs. While ingestion of any plant material can potentially cause mild stomach upset in sensitive individuals or animals, there are no known reports of serious toxicity or harmful reactions specifically associated with Astelia banksii. It does not contain known irritants or toxins commonly found in problematic ornamental plants. Therefore, it is typically regarded as a safe plant to have in gardens accessible to children and pets.

Common Problems

Pests:

• Scale insects (less common, but can occur in sheltered or stressed plants)
• Mealybugs (infrequent problem)

Diseases:

• Root rot (occurs in poorly drained or waterlogged soil)

Other:

• Leaf tip browning (often due to prolonged drought, excessive salt exposure, or sometimes poor soil conditions)
• Leaf damage (from severe frost or physical injury)

Rarity & Value

Rarity:

Astelia banksii is not considered rare in its native New Zealand habitat where it is relatively common in its specific ecological niche. Its rarity in cultivation depends more on geographical location and availability through nurseries. While the species itself is readily available in regions where native New Zealand plants are popular, specific cultivars with unusual leaf colour (e.g., very bronze or heavily variegated forms) or particularly robust growth habits might be less common and therefore considered more ‘rare’ by collectors or enthusiasts. Its propagation by division is straightforward, which generally prevents it from becoming commercially rare unless demand significantly outstrips supply or a specific form is slow to bulk up.

Value:

The market value of Astelia banksii specimens is primarily influenced by size and maturity. Larger, well-established clumps command higher prices than small divisions or young plants. The overall health and appearance of the plant, such as vibrant foliage colour and good form, also contribute to its value. For standard green or silver forms, the value is generally moderate, reflecting its relative ease of cultivation and propagation by division. However, selected cultivars, particularly those with striking bronze foliage or stable variegation, can have a higher value due to their ornamental appeal and potentially slower propagation rate or limited availability. Collector trends can also temporarily influence demand and price for specific attractive forms. Provenance is less a factor for this species unless it’s a wild-collected specimen (which is generally restricted for conservation) or a historically significant plant from a specific garden, neither of which commonly affects market value for typical garden plants.