Phormium: Dramatically Upright

Heather Stephenson

At Beds & Borders, we have been growing and propagating many varieties of phormium for more than 20 years. Phormium is a New Zealand native that is commonly referred to as New Zealand flax. It is similar to a true flax plant because of its long leaf fibers, which were often used in the making of textiles.

Phormium is one of our garden favorites because of its structure and versatility. Grown primarily for its interesting foliage, it’s an exotic plant with an upright nature. Its broad sword-like leaves are a wonderful garden accent or garden focal point. Phormium drew our attention for many reasons—its architectural presence, stunning texture and color. They also add dramatic interest to mixed containers and garden borders. Phormium requires very little care and adapts well in many environmental conditions while providing four seasons of maintenance-free color.

Its increased popularity has resulted in many crosses between the two original species of Phormium tenax and Phormium cookianum. In recent years, there have been many new hybrid varieties of phormium that are now readily available in many different colors, sizes and textures.

Cultural Tips
Propagation: Done by division. Separate younger plants (divisions) from older plants.
 
Timing: Phormium can be divided in spring or fall. It has a long crop time, averaging 16 weeks.

Pot sizes: Recommended pot sizes are 4.5 in. to 8 in., depending on division size.

Potting medium: Phormium prefers well-drained soil and, if possible, with sand or bark often found in a standard perennial mix. Avoid using coir, peanut or rice hulls in the mix to prevent pest damage.

Temperature: 60F to 90F (16C to 32C) for growth. Phormium can handle a light frost. Hardy to USDA Zone 8.

Light: This plant grows best in full sun, but will tolerate lower light.

Water: During propagation, keep phormium moist. Older plants will tolerate moderate to dry conditions.

Feed requirements: Provide low to moderate feed every six to eight weeks only when actively growing.
pH: Slightly acidic.

Disease, insects and pests: Phormium is susceptible to mealybugs. Spider mites can be a problem in humid conditions.

Additional notes: Phormium is very slow growing. It doesn’t like to be over-potted, planting at a high plant depth. Colder temperatures intensify the colors.  GT

Heather Stephenson is director of product development and marketing for Beds & Borders, Inc., Laurel, New York.