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Phormium Cookianum

Phormium Cookianum

Native Mountain Flax, NZ Flax Plant

$12.50
$12.50
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Taxes included.
Pot Size/Grade

Phormium cookianum, commonly known as Mountain Flax, is a graceful New Zealand native prized for its soft arching foliage, elegant form and exceptional versatility in the landscape. Unlike the stronger upright habit of traditional flax varieties, this NZ flax plant develops gently cascading leaves that create movement and texture in gardens year-round.

Naturally occurring across coastal and mountainous regions of New Zealand, Phormium cookianum is well adapted to a wide range of conditions including wind, frost and exposed sites. Its broad green foliage forms attractive evergreen clumps that work beautifully in native planting schemes, contemporary landscapes, mass planting and large containers.

During summer, mature plants produce tall flower spikes carrying nectar-rich tubular flowers that attract tūī and other native birds. Hardy, low maintenance and distinctly New Zealand, Mountain Flax is an excellent choice for gardeners wanting year-round structure with a softer more natural appearance.

Whether used as a feature specimen, planted in groups or incorporated into native gardens, Phormium cookianum delivers reliable performance and timeless appeal.

  • Expected 5 Year Height 1.5 M Width 1.8 M

Is Phormium Cookianum suitable for my garden?

Phormium Cookianum is best suited in a position that gets

  • Full sun
  • Partial shade

Phormium Cookianum is

  • NZ Native
  • Flowering
  • Drought resistant
  • Attracts pollinators
  • Drought resistant once established
  • Frost Tolerant
  • Wind Tolerant
  • Coastal Friendly
  • Fast-growing
  • Cold hardy
  • Evergreen

Phormium Cookianum will thrive in soil that is

  • Clay
  • Sandy
  • Free draining
  • Normal

How to establish your Phormium Cookianum?

Position
Plant in full sun to partial shade. Full sun encourages stronger growth while partial shade can help maintain lush foliage colour in hotter locations.

Soil
Phormium cookianum performs best in well-drained soils but is highly adaptable and tolerates a wide range of conditions once established.

Watering
Water regularly while establishing. Once settled, Mountain Flax becomes drought tolerant and generally only requires supplemental watering during prolonged dry periods.

Feeding
Apply a balanced slow-release fertiliser in spring to encourage healthy fresh foliage and vigorous growth.

Spacing
Allow approximately 1.5–2m between plants depending on the desired finished effect and planting density.

How to maintain your Phormium Cookianum once established?

Very low maintenance once established. Remove older or damaged leaves at the base throughout the year to maintain a tidy appearance.

Cut spent flower stems back after flowering. Older clumps may be divided every few years to rejuvenate growth or propagate additional plants.
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