Overview

Phormium tenax 'Purple Giant' is a perennial in the genus Phormium, part of the Asphodelaceae family, with evergreen foliage. It typically grows around 3.0 m tall. Phormium tenax 'Purple Giant' grows best in full sun, and tolerates most soils. Its UK hardiness is rated H4. Suggested uses include ornamental, borders and architectural plant. It is native to New Zealand.

About

Phormium tenax 'Purple Giant' is a large evergreen perennial New Zealand flax grown for its architectural, upright clump and tall stature. It can reach around 3.0 m and holds its strap-like foliage year-round. It flowers in the UK from June to August. Plant it in full sun on soils that are sandy, loamy or clay and that remain moist to wet but not permanently waterlogged.

Wikipedia contributors, CC BY-SA 4.0 — Phormium tenax

About the genus

Phormium is a genus of two plant species in the family Asphodelaceae. One species is endemic to New Zealand and the other is native to New Zealand and Norfolk Island. The two species are widely known in New Zealand as flax or their Māori names wharariki and harakeke respectively, and elsewhere as New Zealand flax or flax lily, but they are not closely related to the Northern Hemisphere's flax, which is native to the region extending from the eastern Mediterranean to India and has been used by humans since 30,000 B.C.

Wikipedia contributors, "Phormium", CC BY-SA 4.0 — Phormium

In the garden

Phormium tenax 'Purple Giant' belongs to the Asphodelaceae and originates from New Zealand; it forms an evergreen clump valued for strong, upright foliage and its seasonal flowering from June to August. The cultivar’s mature height of about 3.0 m gives it a distinctly architectural presence in the garden. Position it in full sun and choose a site with moist but well-drained soil; it will also tolerate heavier clay or sandy soils so long as they do not remain stagnantly dry. Its UK hardiness rating is H4 (average), so it is suited to most mainland locations in Britain; for reference it corresponds to roughly USDA zones 8–10. Moist ground or seasonal wetness is acceptable, making it useful where other ornamentals might struggle with damp conditions. Use Phormium tenax 'Purple Giant' as a structural specimen, at the rear of a mixed border, or as an architectural focal point in a planted terrace. Allow room for a tall clump and site it where the foliage can be seen unfurled; the plant’s height and permanence mean it will define a space season after season, so bear its 3.0 m reach in mind when siting.

Growing conditions

Best soil and position for Phormium

Sunlight

Full sun

Soil type

Sandy, Loamy, Clay

Soil moisture

Moist but well-drained, Wet

Exposure

full sun

UK hardiness

H4

Plant details

Phormium tenax 'Purple Giant' size, habit and characteristics

Plant type

perennial

Foliage

Evergreen

Height

3.0 m

Suggested uses

ornamental, borders, architectural plant

Native to

New Zealand

Care notes

Pruning and caring for Phormium tenax 'Purple Giant'

Cultivation

Prefers moist but well-drained soil; tolerates wet conditions; plant in full sun for best leaf color.

Pruning

Remove old or damaged leaves to maintain appearance; cut flower stalks after blooming.

Propagation

Division of clumps in spring or autumn.

Frequently asked questions