Does it need pruning?

Only remove dead or damaged leaves at the base to keep it tidy.

Can I grow it in a pot?

Yes, it thrives in large containers if provided with excellent drainage.

Plant guide

New Zealand flax.

Phormium tenax

Pronounced FOR-mee-um TEN-aks

Also known as Lowland flax, New Zealand Flax, New Zealand hemp, New Zealand-flax, New Zealand-hemp, Swamp flax, harakeke

New Zealand flax — Photo by Colin Meurk (CC BY) via iNaturalist

This striking plant is native to New Zealand and features long, sword like leaves that add a bold architectural element to any space. It is quite hardy and thrives in a variety of conditions if given enough light. You will love how its dramatic foliage stands out in a garden or large container.

Another photo of New Zealand flax — Photo by Arnim Littek (CC BY) via gbif

At a glance

Care level: Easy
Plant type: Perennial
Light: Full sun to partial shade
Indoor light: Bright indirect
Water: Every 7 to 14 days
Mature size: 6 to 10 feet
Growth rate: Medium
Hardiness: USDA 8 to 11
Bloom time: Late spring to mid summer

Care

Make sure the soil drains well to keep the roots happy. Watch for drooping leaves which often signal that the plant needs more light or a drink. Wipe the leaves occasionally to keep them dust free and healthy.

Watering: Water when the top inch of soil feels dry to the touch.
Feeding: Apply a balanced liquid fertilizer during the active growing season.
Pruning: Remove dead or damaged leaves at the base to keep the plant tidy.
Repotting: Repot only when the plant becomes root bound in its container.
Soil: Well draining loamy soil
Soil pH: 6.0 to 7.5
Temperature: -10 to 35°C
Humidity: 40 to 70%
Drought tolerance: High
Lifespan: Perennial, typically 20 plus years.
Deer and rabbits: High

Signs it needs repotting

Roots growing out of the drainage holes.
The plant becomes top heavy and unstable.
Growth slows significantly during the growing season.

Safety

People: The plant is generally considered non-toxic, but the sharp leaf edges can cause mechanical injury.
Pets: This plant is generally considered non toxic to cats and dogs.
Children: The rigid, sharp leaf tips pose a risk of eye injury to small children playing nearby.
Contact allergens: The stiff, serrated leaf margins can cause skin abrasions.
Airborne allergens: Pollen may cause mild reactions in sensitive individuals.
Edibility: The plant is not considered edible for humans.

How to identify it

Long sword shaped leathery leaves
Leaves grow in a fan pattern
Mature plants produce tall flower stalks
Foliage often shows colorful margins

Height: 1.5 to 3m
Spread: 1 to 2m
Leaves: dark green, bronze, evergreen
Flowers: red, yellow, orange, 2 to 4cm
Fruit: black, Autumn

Problems to watch for

MealybugsCommon
Scale InsectsCommon
Brown Leaf EdgesUncommon
Root RotUncommon

By symptom

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Growing it

Propagation: division, seed
When to plant: spring, early autumn
Overwintering: In colder regions, protect the crown with a layer of mulch. If kept in a container, move it to a sheltered spot away from freezing winds.
In containers: It grows very well in large containers, provided the pot is at least 50 centimeters wide to accommodate its root system.

Division

1. Dig up the mature clump in spring.
2. Use a sharp spade to divide the root mass into smaller sections.
3. Ensure each section has healthy leaves and roots.
4. Replant immediately in well draining soil.

Pair this plant with other drought tolerant coastal species to simplify your maintenance routine.

Grows well with

Hebe — They share similar environmental needs and provide a nice textural contrast.
Cordyline — These plants create a classic architectural look together in a garden bed.

Similar species

Mountain Flax — It is a smaller, more compact relative that is better suited for smaller gardens.

Science

Family: Asphodelaceae
Genus: Phormium
Order: Asparagales
Class: Liliopsida
Native range: New Zealand and Norfolk Island.
Conservation: It is not currently threatened, but wild harvesting should be done sustainably.

It grows in diverse habitats from swamps to mountain slopes, relying on its tough fibers to withstand wind.

Value to wildlife: nectar source
Pollinators: birds
Uses: architectural focal point, coastal landscaping, fiber production

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 7/9
Soil reaction: 5/9
Light: 7/9
Temperature: 6/9
Moisture: 5/9
Nutrients: 4/9

Taxonomy resolved against GBIF.

Questions people ask

Does it need pruning?: Only remove dead or damaged leaves at the base to keep it tidy.
Can I grow it in a pot?: Yes, it thrives in large containers if provided with excellent drainage.

Where the name comes from

Phormium comes from the Greek word for basket, referring to its traditional use, while tenax means tenacious or tough.

Good to know

It is commonly known as New Zealand flax despite not being related to true flax.
The flower stalks can reach up to 4 meters in height.
It is highly tolerant of salt spray, making it perfect for seaside gardens.

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This guide was generated with AI and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.