Phormium plants, on average, are tolerant to frost and drought once they are established. Although some of the broad-leafed cultivars, especially those derived from Phormium colensoi are less hardy, they are generally capable of surviving most winters without protection, provided they are not kept in small pots that can freeze solid. Also, Phormiums grown in extremely cold regions in Northern areas may require extra protection. 

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The pretty leaves of this tree are green with red-tinged edges. The leaves take on yellow and orange colours just before they start to shed.

Winter Care For Phormiums

New Zealand flax plants, as they are popularly referred to, are low-maintenance plants capable of surviving winter temperatures down to -5 degrees to 10 degrees Celsius if placed in a sheltered location. 

They are typically not suited for areas that regularly suffer from the long winter cold. Hence, they are most often grown by cold-weather gardeners as potted plants that can be moved indoors or to a cold greenhouse during the winter period. 

Alternative to moving the plant to shelter, the pot can be plunged into a larger container with the base of the plant covered with bark chippings, bracken, or even straw.

Phormium Sundowner

Phormium Sundowner


Can I grow Phormiums in a pot?

Phormiums are plants that make a strong architectural statement, perfect for borders and containers. They are commonly grown in large containers and may need to be acclimatized in spring before returning them outdoors for summer. 

The size of Phormium plants at maturity is dependent on the variety and the growing condition; as many of the plants grown in containers are capable of growing from 1 to 4 feet tall, although Phormium Tenax species can reach up to 10 feet in height.

Phormiums are not limited by being pot-bound, their roots are capable of filling the pot when they are growing well. To avoid growth impediment, it is best to move the plant to a larger pot especially when the roots begin to grow out of the container.

Phormium Soil Requirements

Phormiums are tolerant to most soils and can thrive in poor-quality soils, although, they prefer fertile, moisture-retentive, and well-draining soil. They prefer slightly acidic soil but can thrive in neutral soil. When grown in pots or containers, they can tolerate general-purpose potting compost but prefer peat-based potting compost coupled with slow-releasing fertiliser.

Other types of Phormium we cover:

Phormium Black Adder, Black Velvet, Bronze Baby, Colensoi, Cookianum, Evening Glow, Golden Ray,  Jester, Maori Queen, Pink Stripe, Platts Black, Rainbow Queen / Maiden, Phormium Sundowner, Phormium Tenax, Phormium Tenax Variegatum, Yellow Wave.

Further reading:

Where can I buy Phormiums? 


Last Modified: September 9, 2022