Phormium – commonly called New Zealand flax –is a dramatic plant composed of sword-like, stiffly vertical leaves in a fan pattern. Cultivars often range in colors from yellow-green to dark green with white or yellow stripes.
Phormium bears tall erect panicles of 1 to 2-inch (5cm) tubular blossoms in dull red or yellow. Flowers appear in late summer and autumn.
Use Phormium as an accent plant in a border, lawn, or near a building. Phormium is sturdy and fast-growing. Phormium can tolerate salt air and ocean spray. It can be easily grown as a container plant.
Phormium is a genus of two species of evergreen perennials native to scrub and swamps and hillsides near riverbanks in New Zealand.
Get to Know Phormium
- Plant type: Evergreen perennial
- Growing zones and range: Zones 9 and 10
- Hardiness: Generally Zone 9 south
- Height and width: 5 to 7 feet (1.5-2m) tall and 4 feet wide (1.2m)
- Growth rate: Fast
- Form and habit: Clump-forming
- Foliage: Large, linear, keeled leaves, each folded into a V-shape at the base, and ranging in color from yellow-green to dark green, with many fine stripes
- Flowers: Abundant small, 1-2 inch (2.5-5cm), tubular 6-petaled, dull red or yellow flowers are produced in erect panicles on leafless stems
- Bloom time: Summer
- Uses: Border, by a building, at the edge of a lawn, coastal garden, accent plants, near swimming pools, specimen
- Common name: New Zealand flax
- Botanical name: Phormium
- Family name: Agavaceae
- Origin: New Zealand
Where to Plant Phormium
- Plant Phormium in full sun.
- Plant Phormium in fertile, moist but well-drained soil.
- Where marginally hardy, provide a deep, dry mulch in winter.
- Phormium tolerate salt air and ocean spray, but not dune conditions.
- In areas where they are marginally hardy, select a sheltered, south-facing site and protect plants with a thick layer of dry mulch such as salt hay or weed-free straw over winter.
When to Plant Phormium
- Sow Phormium seed at 55-64°F (13-18°C) in spring.
- Set container-grown Phormium in the garden in spring or autumn.
Planting and Spacing Phormium
- Space Phormium 6 to 10 feet (2-3m) apart.
How to Water and Feed Phormium
- Give Phormium much or little water.
- Feed Phormium with an all-purpose organic fertilizer in spring.
How to Care for Phormium
- Where Phormium is marginally hardy, place a deep, dry mulch over the crown in winter or overwinter the plant indoors.
Phormium Pests and Diseases
- Phormium can sometimes develop leaf spots or crown rot.
- Divide Phormium clumps in spring.
- Sow seed in warming soil or in a warming cold frame in spring.
Phormium Varieties to Grow
- Phormium cookianum, Mountain flax, clump-forming perennial ith broad, arching, linear, light to yellowish green leaves, to 5 feet (1.5m) long. Tubular, yellow-green flowers, to 1.5 feet (4cm) long, are produced in upright panicles, 6 feet (2m) long, in summer. To 6 feet (2m) tall and 10 feet (3m) wide. New Zealand.
- P. tenax, New Zealand flax, clump-forming perennial with rigid, upright, linear leaves, to 10 feet (3m) long, dark green above, blue-green beneath. Thick, red-purple panicles, to 12 feet (4m) long, of tubular, dull red flowers, 2 inches (5cm) long, are borne in summer. To 12 feet (4m) tall and 6 feet (2m) wide. New Zealand.