Overview

Phormium tenax is a clump forming perennial in the genus Phormium, part of the Asphodelaceae family, with evergreen foliage. It typically grows around 3.0 m tall. Phormium tenax grows best in full sun, and tolerates most soils and neutral pH. Its UK hardiness is rated H4. Suggested uses include ornamental and fibre production. It is native to New Zealand.

About

Phormium tenax is an evergreen perennial from New Zealand that forms tall clumps, reaching about 3.0 m. It prefers a sunny position and reliably holds its leaves year-round. Planting needs include moist but well-drained or wet soils across sandy, loamy or clay types. It flowers in the UK from June to August.

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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.

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In the garden

Phormium tenax is an evergreen perennial native to New Zealand, grown both for its ornamental presence and for fibre production. Mature plants can reach roughly 3.0 m in height and present a clear vertical accent in the garden. Given its origins, it suits warm, sunny situations where its form can be seen against a border or as a specimen. Place Phormium tenax in full sun and choose any of the common garden soils—sandy, loamy or clay—provided the soil remains moist; the species will also tolerate consistently wet spots. It is rated H4 for the UK, meaning it has average hardiness and will tolerate typical UK winters in most areas, although the coldest sites can be more testing. In USDA terms it corresponds to zones 8–10. Use it where a tall, evergreen upright element is required: as a focal point at the back of a mixed border, alongside water features where soils stay damp, or in larger containers where drainage and moisture can be managed. It is valued both for garden presence and for fibre uses. Expect the flowering period in the UK to be from June to August, when flowering stems rise above the leaves.

Growing conditions

Best soil and position for Phormium

Sunlight

Full sun

Soil type

Sandy, Loamy, Clay

Soil pH

Neutral

Soil moisture

Moist but well-drained, Wet

Aspect

South-facing

Exposure

Sheltered

UK hardiness

H4

Plant details

Phormium tenax size, habit and characteristics

Plant type

Perennial

Habit

Clump forming

Foliage

Evergreen

Height

3.0 m

Suggested uses

Ornamental, Fibre production

Native to

New Zealand

Care notes

Pruning and caring for Phormium tenax

Cultivation

Prefers moist, well-drained soil; tolerates wet conditions; full sun exposure

Pruning

Remove old flower stalks and damaged leaves to maintain appearance

Propagation

Division, seed

Pest resistance

Phormium mealybug

Disease resistance

Honey fungus

Frequently asked questions