New Zealand Flax Growing Guide

Phormium tenax cultivars

Crop Rotation Group

Miscellaneous ●

Soil

Fertile, well-drained soil enriched with compost, with a neutral to slightly acidic pH.

Position

Full sun to partial afternoon shade.

Frost tolerant

No. New Zealand flax is a perennial evergreen in climates where the soil does not freeze in winter, but it is best grown as an annual or container plant in temperate climates. Well-rooted plants that are mulched in winter may survive temperatures to -5°C (23°F).

Feeding

Drench with a liquid organic fertiliser monthly throughout the summer.

Spacing

Single Plants: 60cm (1' 11") each way (minimum)
Rows: 60cm (1' 11") with 60cm (1' 11") row gap (minimum)

Sow and Plant

New Zealand flax can be started from seed, but cultivars with showy purple or variegated leaves are propagated vegetatively and must be purchased as plants. Set out plants in mid spring after the soil begins to warm. Young plants need water when they are actively growing. A surface mulch suppresses weeds and retains soil moisture while making the plants look more attractive. Propagate New Zealand flax by separating rooted offshoots from the outside of the clump and potting them up in spring or early summer. Large plants can be cut into pieces and replanted, preferably in spring.
Our Garden Planner can produce a personalised calendar of when to sow, plant and harvest for your area.

Notes

Phormium’s long, strappy leaves have long been used by New Zealand’s Maori people as fibre for ropes, baskets and houses, hence the common name of flax. When grown in the ground in hospitable climates, New Zealand flax produces a tall red flowering spike in late summer. Young plants grown in containers seldom bloom, but make resilient texture plants in mixed containers. Where winters are cold, plants can be brought into a cool basement or garage where temperatures stay above 10°C (50°F) and allowed to become semi-dormant. Trimmed back and provided with only enough water to keep them alive, the plants should perk up in spring and begin to regrow.

Harvesting

Older leaves of New Zealand flax can be cut near the base in summer, cut into strips, and woven into baskets and other crafts.

Planting and Harvesting Calendar

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Pests which Affect New Zealand Flax

Aphids (General)

Slug

Snail