Plant Finder
 
perennial

Mountain Flax

Phormium cookianum

Add To My Wish List

 
Mountain Flax (Phormium cookianum) at Hana Gardens

Mountain Flax flowers

(Photo courtesy of NetPS Plant Finder)

Height:  4 feet

Spacing:  4 feet

Sunlight:  full sun  partial shade  full shade 

Hardiness Zone:  8b

Other Names:  New Zealand Flax, Phormium colensoi

Description:

A stunning perennial featuring shiny, olive green, sword-like leaves that arch gracefully; yellow flowers on arching spikes in spring, followed by attractive seed pods; a great accent in the garden or borders, or as a center for a mixed container

Ornamental Features

Mountain Flax features showy spikes of yellow tubular flowers with orange overtones rising above the foliage from late spring to early summer. The flowers are excellent for cutting. Its attractive large glossy sword-like leaves remain olive green in color throughout the year. The fruits are showy black pods carried in abundance from late summer to early fall.

Landscape Attributes

Mountain Flax is an open herbaceous evergreen perennial with a shapely form and gracefully arching foliage. Its relatively coarse texture can be used to stand it apart from other garden plants with finer foliage.

This is a relatively low maintenance plant, and is best cleaned up in early spring before it resumes active growth for the season. Deer don't particularly care for this plant and will usually leave it alone in favor of tastier treats. It has no significant negative characteristics.

Mountain Flax is recommended for the following landscape applications;

  • Accent
  • Mass Planting
  • General Garden Use
  • Container Planting

Planting & Growing

Mountain Flax will grow to be about 4 feet tall at maturity, with a spread of 4 feet. When grown in masses or used as a bedding plant, individual plants should be spaced approximately 4 feet apart. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 10 years. As an evegreen perennial, this plant will typically keep its form and foliage year-round.

This plant performs well in both full sun and full shade. It prefers to grow in average to moist conditions, and shouldn't be allowed to dry out. This plant should not require much in the way of fertilizing once established, although it may appreciate a shot of general-purpose fertilizer from time to time early in the growing season. It is not particular as to soil type or pH, and is able to handle environmental salt. It is somewhat tolerant of urban pollution. This species is not originally from North America. It can be propagated by division.

Mountain Flax is a fine choice for the garden, but it is also a good selection for planting in outdoor pots and containers. Because of its height, it is often used as a 'thriller' in the 'spiller-thriller-filler' container combination; plant it near the center of the pot, surrounded by smaller plants and those that spill over the edges. It is even sizeable enough that it can be grown alone in a suitable container. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.

 
 
Hardiness Zone Plant Height Minimum Sunlight
Characteristics
Accent  Massing  Garden  Container 
Applications
Flowers  Fruit  Foliage Color  Texture  Plant Form 
Ornamental Features