Bush Flax

Botanical name: Astelia grandis
Synonym: Astelia nervosa var. grandis
Common name(s): Bush Flax, Kakaha, Swamp Flax

About:
The largest of New Zealand’s astelias, forming massive bold clumps of broad flax-like foliage. This impressive wetland and forest species is known for its olive-green leaves, silvery undersides, reddish-purple midribs, and bright orange berries on female plants.

Natural habitat:
Occurs naturally in lowland swamp forest, kahikatea forest, wet gullies, stream margins, lakeshore scarps, forest floors, and swampy coastal forest.

Growing environment:
Part shade, Moist soils, Wet soils, Heavy soils & Sheltered conditions.
Thrives in damp fertile soils and tolerates swampy or periodically waterlogged ground.

Endemic distribution:
Endemic to New Zealand.
Most common in warmer regions of the South Island within wet lowland forest ecosystems.

Height:
Approximately 1.5–2 m tall

Width:
Forms large dense clumps approximately 1.5–2 m across

Flowering:
Spring
Produces pale white to cream flowers from September to October.

Fruiting:
Summer
Bright orange fleshy berries mature from December to February on female plants.

Uses:

• Wetland restoration planting
• Native forest understory planting
• Bird and lizard habitat creation
• Architectural landscaping
• Moist and swamp garden planting
• Shelter and texture planting

Appearance:

Growth habit:
A robust evergreen perennial forming large upright architectural clumps.

Leaves:
Very broad upright flax-like leaves, olive-green above with silvery undersides and reddish-purple midribs. Leaves are stiff, bold, and less tapered than those of Astelia fragrans.

Flowers:
Pale white to cream flowers carried on stout upright flowering stems.

Fruit:
Produces clusters of bright orange fleshy berries highly attractive to birds and lizards.

Ecology:
An important wetland and lowland forest understory species providing shelter, structure, and food resources for native fauna. Berries are dispersed by birds through frugivory.

Associated wildlife:
Frequently visited by native birds, insects, and lizards attracted to the berries and dense foliage.

How to grow:
Best planted in moist fertile soils in sheltered semi-shade. Excellent beside waterways, ponds, swales, and damp forest gardens. Tolerates heavy soils and wet conditions once established.

Propagation:
Can be propagated from fresh seed or by division of established clumps. Cold stratification may improve germination speed and consistency.

Cultural uses:
Valued as part of native forest ecosystems within Māori ecological knowledge. Also the orange berries were traditionally eaten raw.

Garden value:
A spectacular large-scale native foliage plant ideal for wetland restoration and lush subtropical-style native landscapes. Particularly effective in large gardens where its bold architectural form and vivid fruit can be fully appreciated.