Phormium cookianum Black Adder · Phormiaceae

New Zealand Flax

⚠️ Not safe for petsPerennial life cycle with continuous growth.60 to 90 cm

LightFull sun

WaterMedium, allows drying between waterings

DifficultyEasy

ColdResistant down to -5 degrees Celsius.

Full sunMedium, allows drying between wateringsEasyResistant down to -5 degrees Celsius.

Description & origin

New Zealand Flax is a perennial plant known for its long, narrow leaves. The Black Adder variety features a striking dark color, perfect for enhancing any outdoor space.

Size

Maintains an upright and compact habit.

Foliage

Leaves are long, narrow, and dark-colored, giving an elegant appearance.

Flowering

Produces flowers on tall spikes, but flowering is not the main attraction.

Detailed care

Light

Prefers full sun but tolerates partial shade.

Soil

Well-drained soil rich in organic matter.

Watering

Water moderately, allowing the soil to dry between waterings.

Temperature

Resistant to low temperatures but should be protected from severe frosts.

Fertilising

Fertilize in spring with a balanced fertilizer.

Repotting

Transplant in spring when temperatures begin to warm.

Pruning

Light pruning to remove dry or damaged leaves.

Propagation

Easily propagated by division of clumps.

Common problems

Insect pests

May be affected by aphids and scale insects, which should be controlled with natural insecticides.

Burnt leaves

Excessive sun exposure can cause leaf burn, especially in very hot climates.

Root rot

Overwatering can lead to root rot, so it's important to ensure good drainage.

Uses & curiosities

In the garden

Ideal for borders and beds
Attracts pollinators like bees
Excellent for container planting

Other uses

Perfect for creating contrasts in gardens.

Did you know…

This plant is native to New Zealand and is quite resilient to adverse conditions. Its leaves can reach up to one meter in height.