Common Name: New Zealand Flax

General Information

Phormium tenax is a evergreen perennial plant, forming a large clump of leaves and spreading by means of stout rhizomes. The erect leaves are of a hard, tough texture, rigid except at the tip, around 10 - 12cm wide and up to 2.5 metres tall. A flowering stem up to 4.5 metres tall is produced in the summer[].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It has been considered for commercial cultivation for its fibre, though there is some difficulty in mechanically extracting the fibres[]. The plant is often grown as an ornamental, valued especially for its striking architectural appearance.

Known Hazards

None known

Botanical References

, ,

Range

New Zealand - North, South, Chatham and Norfolk Islands

Habitat

Lowland swamps and intermittently flooded land, North South Stewart, Chatham and Auckland Islands[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Perennial
Height	3.00 m
Cultivation Status	Ornamental, Wild

Cultivation Details

Phormium tenax is a moderately cold-hardy plant, tolerating temperatures down to about -11°c[], but it has been killed in very severe winters in Britain[]
Prefers a rich loamy soil[] but is not too fussy, succeeding in peaty soils and in boggy moorland[]. Tolerates light shade[] but prefers full sun[]. Plants can be grown in quite coarse grass, which can be cut annually in the autumn[]. Prefers a sheltered position[] but tolerates maritime exposure[]. Plants tolerate occasional flooding with saline water[].
A polymorphic species[], there are many named varieties grown in Britain[, ]. This species hybridizes readily with Phormium colensoi and there are many named forms that may be hybrids with that species[].
This plant has been considered for commercial cultivation for its fibre, though there is some difficulty in mechanically extracting the fibres due to the presence of a gum in the leaves. An alkali has been successfully used to break down the gum but this weakens the fibre. The Maoris had selected many different cultivars for different uses[].
Members of this genus are rarely if ever troubled by browsing deer or rabbits[].

Edible Uses

The roasted seed is used as a coffee substitute[, ].

An edible nectar is obtained from the flowers[]. Very wholesome eating[]. A long hollow grass-stalk or straw is used to suck it out of the flowers[].

An edible gum is obtained from the base of the leaves[].

Medicinal

The Maori used the plant as an antiseptic, a purgative, to treat burns and as a splint for broken bones[].

Other Uses

A very high quality pliable fibre is obtained from the leaves[, , , , ]. It is used in the manufacture of ropes (they are not very strong[]), twine, fine cloth etc. The fibre can also be used for making paper[] The leaves are harvested in summer, they are scraped to remove the outer skin and are then soaked in water for 2 hours prior to cooking. The fibres are cooked for 24 hours with lye and then beaten in a ball mill for 4 hours. They make a cream paper[].

The split leaves can be used to make nets, cloaks, sandals, straps etc[]. They are also used in making paper and for basket making[, ].
A strip of a leaf is an excellent emergency string substitute for tying up plants in the garden, it can be tied into a knot without breaking[].

The leaf pulp, after the fibre has been removed, can be fermented to make alcohol[].

A gum found in the leaves is used as a paper glue[].

A brown dye is obtained from the flowers[], it does not require a mordant[].
A terra-cotta dye is obtained from the seedpods[]. A mauve can also be obtained[].

The flowers are rich in tannin[].

Propagation

The seed is best sown as soon as it is ripe in a cold frame. Sow stored seed in late winter in a cold frame. Germination is sometimes poor but should take place in 1 - 6 months at 15°c. The seedlings are very variable. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. The seed remains viable for about 12 months in normal storage[].
Division in spring as growth commences. Very easy, larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer.