How to Plant and Grow New Zealand Flax

New Zealand flax can be used instead of ornamental grass in areas where you need more texture and a dash of color. This low-maintenance plant has no problem with heat in the summer and works well in containers. In Zones 9-11, New Zealand flax can be grown as an annual or evergreen perennial.

The striking lance-shaped leaves of New Zealand flax grow in erect clumps and come in several bold colors. All of these plants previously came in foliage shades of green with a few bronze-red. Now, there are countless variegated forms in differing heights and mixes of color, including pinks, whites, reds, burgundies, and every shade in between.

Where to Plant New Zealand Flax

In most regions, New Zealand flax is grown as an annual, although it can be taken indoors to overwinter and brought back out when the weather warms in spring. These plants grow through the winter as perennials in zones 9-11, where they can become quite large, especially when in the ground. In containers, the size is usually a little more restrained, but they can still quickly fill pots.

Plant in well-draining soil or use potting soil or soilless medium for containers. Locate in full sun with some afternoon shade so the plants will have the most intense coloration and the best, most dense habits. However, some varieties, especially ones with large amounts of white foliage, do better in partial shade because they're more susceptible to leaf burn.

How and When to Plant New Zealand Flax

In areas where they are hardy, plant New Zealand flax nursery-grown plants in spring along with other perennials. Make sure to give these plants lots of room to grow up and out. Space dwarf varieties 1 to 2 feet apart and larger plants 3 to 4 feet apart. Dig a hole twice the width of the container and the same height. Slide the plant out of the container and gently rub the roots to loosen them if they are root bound. Set the plant in the hole and hold it upright with one hand while backfilling the hole with soil. Press down on the soil to remove air pockets, and then work a slow-release balanced fertilizer into the soil around the plant, following the product instructions for the correct amount. Water the plant.

New Zealand flax does equally well in containers as in gardens. Fill the container with a high-quality potting mix. Leave it outdoors for the summer, watering regularly, but bring it in when the temperature drops into the 50°F range. Any temperature colder than that will kill the plant.

New Zealand Flax Care Tips

Patience is needed to see New Zealand flax grow to its full height and width.

Light

Generally, New Zealand flax prefers full sun, but afternoon shade is beneficial for brightly colored foliage.

Soil and Water

New Zealand flax grows in any average, well-drained soil. These plants like to remain evenly moist, but once they're established, they do fine with drought now and then. However, depending on the parentage of a specific cultivar, some may require a little more water than others.

Temperature and Humidity

Because New Zealand flax is hardy only in warm zones, gardeners in cooler locations find better success growing their plants in containers and bringing them inside for the winter. If grown outdoors, mulch heavily to protect them after they die back for the winter.

Fertilizer

The New Zealand flax needs little or no fertilizer. Add compost annually to plants.

Pruning

Prune in the fall or in the spring. Cut off dead or dying branches and leaves at their base. If your plant has been damaged by cold weather, cut it down to its base. It may be that the roots are still healthy, and the plant will grow back.

Potting and Repotting New Zealand Flax

New Zealand flax does well in pots. Use a high-quality organic potting mix and water it regularly during the summer. Bring pots indoors when the weather gets below 50ºF to protect the plants from frost damage. They do well inside when placed where they stay cool but get plenty of sunlight. Plants may not need much water during the cold months.

Pests and Problems

Outdoor New Zealand flax can become infested by mealybugs, sometimes to the point of being unsalvageable. If one of your plants has this problem, it's best to toss it out and start growing a new one.

Indoor plants may have problems with common houseplant insects. Use horticultural soap to clean the plants of these bugs.

How to Propagate New Zealand Flax

If plants become too large, they can be divided to make more new plants. Dig up the plant with a shovel, being careful not to damage the roots or rhizomes, and cut it into smaller chunks or, if possible, gently separate clumps into pieces with several growths per plant. Each section should have roots, a portion of rhizome, and at least one leaf. Then replant the sections in the garden or plant them in a container and water well.

Although New Zealand flax can be grown from harvested seed, the resulting plants won't necessarily resemble the parent plant. Harvest the seed from spent blooms in late summer or fall. Prepare a container with moist seed-starting mix. Sow the seeds sparingly across the surface, pressing them into the growing medium. Cover with a thin layer of medium and water them. Put the container in a warm place; germination occurs at around 60ºF. Expect to see seedlings in about a month.

Types of New Zealand Flax

'Dark Delight' New Zealand Flax

Phormium 'Dark Delight' has evergreen 1- to 2-inch-wide strap-shaped leaves in dull purple. This hybrid has leaves 4 feet long. Zones 9-11

'Rainbow Sunrise' New Zealand Flax

Charming Phormium 'Rainbow Sunrise' (also called Maori Sunrise) has salmon pink or yellow leaves edged with bronze. It grows 2 to 4 feet tall and wide.

'Guardsman' New Zealand Flax

Phormium 'Guardsman' can't be missed in the garden. This impressive plant stands as tall as 7 feet, and the 1 to 2-inch leaves are a stunning mix of burgundy and red. It tolerates seaside conditions and is drought-tolerant.

'Wings of Gold' New Zealand Flax

The leaves of Phormium 'Wings of Gold' are green with a yellow margin and tinges of red throughout the year. This dwarf version of the usually much larger New Zealand flax plants grows only 2 to 2 1/2 feet tall and has a rounded mound appearance.

'Yellow Wave' New Zealand Flax

Phormium 'Yellow Wave' has an arching habit, unlike many New Zealand flax plants. The 2-inch wide leaves have a bright yellow center that fades to light, bright green with a darker green edge. It grows to 3 to 4 feet and is wider than it is tall.

New Zealand Flax Companion Plants

Phlox

There are several different kinds of phlox. Garden and meadow phlox produce large panicles of fragrant flowers in many colors. They add height, heft, and charm to a border. Low-growing wild Sweet William, moss pinks, and creeping phlox are effective as groundcovers at the front of the border, and as rock and wild garden plants, especially in light shade. Zones 4-8

Perennial Sunflower

Perennial sunflower is imposingly tall and floppy with large (up to 4 inches) bright yellow flowers forming loose clusters. Excellent for cut flowers. Zones 4-9

Dahlia

Dahlia flowers form on branching, fleshy stems or open on the bedding-plant types mid to late summer. All dahlias are fodder for seasonal cut bouquets. The blooming season extends into fall and is only halted by the first frost. Zones 8-10

Anemone

Anemones are delicate flowers atop slender stems, giving them their common name—windflower. Depending on the type, anemones bloom in spring, summer, or fall, with pretty, slightly cupped flowers in rose, pink, or white rising over distinctive, deeply lobed foliage. Zones 4-8

Garden Plans for New Zealand Flax

Classic Container Garden Plan

Classic shapes and lush floriferous plants combine beautifully in this shade-loving garden plan.

Fall Deckside Garden Plan

Light up your deck each fall with this high-color garden plan.

Drought-Tolerant Slope Garden Plan

Tame a tough-to-mow slope with this beautiful, easy-care plan.