Complete Guide to Phormium Tenax: How to Plant & Care for New Zealand Flax

Read our complete guide to Phormium Tenax Plants for everything you will ever need to know! Tips for planting and caring for "New Zealand Flax"
Pinterest LinkedIn Tumblr

If you’re looking for an aesthetically pleasing, tropical-looking, easy to care for, hardy, evergreen, and versatile plant to add to your outdoor landscape or indoor terrarium, consider New Zealand flax (Phormium tenax).

As the name suggests, this plant is native to New Zealand, where it is simply referred to as “flax”.

It is an evergreen perennial and is a part of the Asphodelacea family, of which there are more than 900 different species of plants. Phormium tenax is a clump-forming, tender perennial. It got the New Zealand Flax moniker because the Maoris of New Zealand used to cultivate the plant to make a form of linen cloth that was quite similar to flax.

They also used it to make baskets and ropes. The leaves weren’t the only parts of the plant that were used; the Maoris used all parts of flax. For example, the roots were used to make natural medicines, the flower pollen was used to make face power, and the old blooming stems were roped together to create rafts.

If you’re interested in adding this interesting, easy to care for plant to your garden, keep on reading to learn more about it, including its appearance, how to plant it, and how to care for it.

New Zealand Flax Appearance

New Zealand flax features large, colorful, spike- or sword-like leaves that shoot up from its base. The color of the foliage varies and can include red, green, yellow, purple, burgundy, and maroon.

There are even variegated varieties that feature a combination of colors and add an eye-catching look to any landscape.

This plant can grow between 6 and 10 feet wide and can reach as tall as 20 feet high, if grown in the proper conditions.

Green New Zealand Flax Seeds, From Amazon

While New Zealand flax is most commonly grown for its foliage, the plant does produce flowers; however, only older and established plants bloom.

Once its reached maturity, it grows long flower stalks that reach out beyond the foliage. The flowers are tubular-shaped and depending on the variety of the plant, they are either yellow or red in color.

The flowers add to the dramatic look of the New Zealand flax plant. While the flowers are showy, they do not produce a noticeable aroma.

Where to Plant New Zealand Flax

While it is considered a perennial, it only returns when it is planted in USDA Hardiness Zones 8 through 10, and while it can survive when planted in Zone 8, it does require protection through the winter; in other words, this plant is not cold-hardy.

When grown outdoors, it will fare best in warm conditions, with winter temperatures ranging between 40 and 50 degrees Fahrenheit. If you live in a region where the temperatures fall below 40 degrees Fahrenheit, be sure to plant New Zealand flax in a container and bring it indoors when the cold weather arrives.

Additionally, when newly planted, New Zealand flax does not like harsh winds, so be sure to plant it in a location that provides shelter from the winds until it is established. Once it is established, it can tolerate the wind.

This plant requires full sun to partial shade. When planting outdoors, make sure to choose a location that offers such lighting conditions. If you are planting it indoors, the ideal location to place it is in a window that receives sunlight from the south or the west.

Live Plant Phormium tenax from Amazon

New Zealand Flax Soil Requirements

New Zealand flax prefers rich, most, well-draining soil that contains organic matter. When growing in a container, instead of a traditional potting soil, opt for an organic mix. If you are planting it outdoors, if the soil is too compact, mix in some perlite or pumice to improve the drainage.

When planted in a container, this plant doesn’t require transplanting unless it begins to outgrow the container it is in. If transplanting is necessary, it’s best to do so in the spring, just before the active growing period begins, which starts in May. A helpful tip: if you are transplanting, if you want to propagate the plant, divide the older clumps.

Watering and Feeding Requirements for New Zealand Flax

Once established, phormium tenax is a drought-tolerant plant; however, it does require a healthy amount of water when it’s first planted, and even established plants like moist soil in the summer months.

  • To determine when to water the plant, insert a finger a few inches into the soil; if it feels dry, it’s time to water.
  • Do note, however, that when watering, you should avoid drenching the plant. If it is allowed to sit in moisture for a prolonged period of time, it can suffer root rot; hence why the soil must be well-draining.
  • When the temperature starts to drop, New Zealand flax does not require a lot of water.
  • Watering about once a week is usually acceptable.

In regard to feeding, New Zealand flax doesn’t require much; however, if you want to maintain a healthy plant, applying liquid fertilizer to the soil once per week during the growing season (May through August) is recommended.

Miracle Gro Liquid all Purpose Plant Food is Perfect

New Zealand Flax Maintenance and Grooming Tips

This plant doesn’t really require a lot of maintenance and grooming. However, horticulturists do recommend removing any spent leaves and flowers to promote healthy growth.

To remove dead leaves and flowers, use a pair of sharp, clean pruning shears or scissors and cut the base of the spent foliage close to the plant.

Propagating New Zealand Flax

If you would like to grow new plants, New Zealand flax is pretty easy to propagate. The easiest way to do so is via division. Separate clumps into smaller sections and then place each one into its own container filled with organic potting soil; make sure the container offers adequate drainage.

Water the newly planted clumps and set them in a warm, sunny location. Once the plants are established, you can transplant them to new containers or into the ground.

Seed propagation is possible; however, it can take a few years for seedlings to grow into mature plants.

Phormium is easy to Propagate
Phormium is easy to Propagate

Diseases and Pests

While phormium tenax is a relatively low-maintenance plant and can thrive in poor-quality soil and drought, it does face a few potential threats.

  • In terms of pests, mealy bugs and scale insects are the biggest threat. These pests eat the foliage and if the infestation is severe enough, they can kill the plant.
  • Inspect the base of the plant on a regular basis. If you find any pests, try removing them with a gentle spray or a cloth. If these methods do not work, you can use a gentle insecticide, such as neem oil.
  • There are two types of diseases that can plague New Zealand flax. One is leaf spot, a fungus disease that causes brownish or grayish, purple-edges spots on the leaves.
  • The second is yellow-leaf virus, which as the name suggests, causes the leaves to turn an abnormal yellow color, which, if left untreated, can kill the plant.
  • The recommended treatment for disease is the removal of the infected leaves.

Suggested Varieties of New Zealand Flax

There are several different varieties of Phormium tenax; in fact, it seems like a new variety is introduced on a yearly basis. What’s more, each new variety has more color variations and is more ornamental than the last.

Garden centers usually carry a handful of different options to choose from, so look around while you’re shopping to see what is available.

Some of the most popular varieties of New Zealand flax include:

  • Jester. Features bronze foliage striped with green and grows approximately 3 feet tall.
  • Bronze Baby. As the name suggests, the foliage is a striking bronze color. This variety grows about 2 feet tall and up to 3 feet wide.
  • Sundowner. The leaves on this variety are green and they feature rose-colored margins. It can grow up to 6 feet tall and wide.
  • Duet. A dwarf plant, this variety grows around 1 foot tall and wide. The leaves are green and feature cream-colored edges. The leaf blades are very stiff.

Landscape Design Tips

New Zealand flax is a wonderful addition to any indoor or outdoor garden. It grows very well in containers (as long as they offer good drainage) and can either be grown alone or accented by colorful annuals.

In the garden, varieties that grow shorter look beautiful as edging. Taller varieties can make a statement when planted in the back of a garden and surrounded by lower growing annuals or perennials.

Planting several together will also create a dramatic look for your landscape.

Phormium works well in containers also
Phormium works well in containers also

Summing it Up

Phormium tenax, or New Zealand flax, is a simple, yet visually appealing, and easy to care for plant. It comes in a variety of species that range in colors from solid green to red and even pink and burgundy.

A lot of species even feature multiple colors. The colors of the spikey foliage create a dramatic look. This plant grows well I containers, and when grown in the proper climate, it can fare very well outdoors, as well.

Hollie Carter

Hollie is a life-long gardener, having started helping her Dad work on their yard when she was just 5. Since then she has gone on to develop a passion for growing vegetables & fruit in her garden. She has an affinity with nature and loves to share her knowledge gained over a lifetime with readers online. Hollie has written for a number of publications and is now the resident garden blogger here at GardenBeast. Contact her at or follow on twitter

Write A Comment