Phormium, a grass-like clump of color in the garden… or pot… or terrace

Phormium grass, New Zealand flax

Phormium is a superb plant with a colorful, abundant and very ornamental clump.

Key facts to remember

Name – Phormium
Family – Agavaceae
Type – perennial

Height – 6 ½ feet (2 meters)
Exposure – full sun
Soil – well-drained

foliage – evergreen Flowering : summer

Planting Phormium

Ideal in a pot on a deck or terrace, it’s also wonderful planted in a sunny garden.

A type of phormium with striped variegated leavesPhormium should be planted ideally in spring in a spot with full sun exposure and in well-draining soil.

Its low hardiness means it will have trouble surviving through cold temperatures (21°F or -6°C). If winter gets any colder, then grow it in a pot and bring it indoors for shelter.

  • In a pot, you’ll only need to put soil mix, perhaps with a little sand mixed in.
  • In the ground, you’ll get a batch ready with garden soil + fresh soil mix, again possibly with sand.
  • In any case, the soil must drain well.

In a pot, phormium will do just fineGrowing phormium in a pot is fully suited to the plant, on the condition that you water when the soil dries out.

Multiply phormium easily through clump division after the blooming in fall.

Sowing seeds is also feasible, but more difficult to succeed in.

Caring for Phormium

Once the blooming has subsided, remove floral scapes from the phormium, cutting them as short as you can reach.

Proper care for phormium leads to very healthy plants

  • Only remove the leaves themselves when they’ve fully dried out.
  • Protect the base in winter with a good layer of dried leaf mulch.
  • If in a pot, bring it under shelter so it won’t freeze, but not to a room with heating.
  • Leaves wither and dry naturally during the life of the plant: remove them when dry.

Mineral mulch truly highlights the colors of this surprising perennial.

Watering phormium 

Water drops on a phormium leafPhormium requires watering when the soil has fully dried out, especially when growing in a container.

In the ground, water abundantly when the weather is hot, especially during the 2 first years.

  • In summer, watering in the evening reduces evaporation and contributes to saving water.

Potted phormium:

Watering for potted phormium must be much more regular than if it’s planted in the ground. If many phormium leaves dry out at once, it’s certainly the sign that it doesn’t get enough water.

Learn more about phormium

A clump of magnificent colors is what phormium brings to your landscaping. This beautiful, bushy perennial adapts particularly well to container growing, simply perfect for your deck or balcony, especially if winter is cold.

Its foliage takes on different hues depending on the variety: purple, bronze, green and sometimes striped. It’s a very trendy plant at the moment, that does great in traditional gardens, zen gardens and also modern designer landscaping.

Phormium in a large landscape with other grasses and shrubs

Another name for this plant is New Zealand flax, which answers the question as to where it is native to. It’s often found in shrubbery and in marshes across the country.

New Zealand flax has been used, even until now, by the Māori peoples for many things, from clothes to basket-weaving. Even the roots have a purpose: they’re good to disinfect wounds.

Smart tip about Phormium

Select different varieties of this plant to grow together in the same flower bed: you’ll be surprised at how much more appealing this will look!


Image credits (edits Gaspard Lorthiois):
CC BY-SA 2.0: Judy Dean, Torquay Palms
CC BY 4.0: Kim & Forest Starr
Public Domain: Brian Toward
CC BY 2.0: Mark Wordy