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Platt's Black New Zealand Flax

Phormium 'Platt's Black'

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Platt's Black New Zealand Flax (Phormium 'Platt's Black') at Chalet Nursery

Platt's Black New Zealand Flax foliage

Platt's Black New Zealand Flax foliage

(Photo courtesy of NetPS Plant Finder)

Platt's Black New Zealand Flax (Phormium 'Platt's Black') at Chalet Nursery

Platt's Black New Zealand Flax

Platt's Black New Zealand Flax

(Photo courtesy of NetPS Plant Finder)

Height:  4 feet

Spacing:  4 feet

Sunlight:  full sun  partial shade 

Hardiness Zone:  (annual)


Possibly the darkest variety with dark brown leaves that appear nearly black; unique and eye catching as a contrasting accent in the garden or massed along borders; also a great center for a mixed container

Ornamental Features

Platt's Black New Zealand Flax's attractive large sword-like leaves remain dark brown in color with distinctive black edges throughout the year. Neither the flowers nor the fruit are ornamentally significant.

Landscape Attributes

Platt's Black New Zealand Flax is an open herbaceous annual 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.

Platt's Black New Zealand Flax is recommended for the following landscape applications;

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

Planting & Growing

Platt's Black New Zealand 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. Although it's not a true annual, this plant can be expected to behave as an annual in our climate if left outdoors over the winter, usually needing replacement the following year. As such, gardeners should take into consideration that it will perform differently than it would in its native habitat.

This plant does best in full sun to partial shade. It prefers to grow in average to moist conditions, and shouldn't be allowed to dry out. It is not particular as to soil type or pH. It is somewhat tolerant of urban pollution. This particular variety is an interspecific hybrid. It can be propagated by division; however, as a cultivated variety, be aware that it may be subject to certain restrictions or prohibitions on propagation.

Platt's Black New Zealand 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. 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
Accent  Massing  Garden  Container 
Foliage Color  Texture  Plant Form 
Ornamental Features