INTRO TO FLAX
New Zealand Flax (Phormium sp.) are large strap-leafed evergreen perennials in the family Phormiaceae.
There are two species in the genus. Phormium tenax, the Coastal Flax, is the larger and more
common plant in cultivation; its long strap leaves in shades of green. The Mountain Flax,
Phormium cookianum (P. coloensoi), is a smaller, more graceful plant.
Both of these plants are useful and attractive in the right situation, but the real gems are the colorful cultivars and interspecific
hybrids that have been recently introduced.
Cultural practices for the flax hybrids are similar to those for the species with a few exceptions. As a general rule the hybrid flax are not as durable as Phormium tenax and are usually less tolerant to extremely hot or cold temperatures, prolonged dry conditions and heavy soil. Sunburn is likely on the cultivars that have the graceful weeping leaves; cold temperatures below 20 F are likely to scald the leaves of these plants as well. In hot inland valleys it would be wise to use these cultivars in bright shade where there is protection from the sun. The upright growing cultivars are affected less by these extremes in temperature. We have found the hybrids to be nearly as drought resistant as Phormium tenax. Plants look much better with occasional irrigation but can survive extensive periods without it. There is a tendency for the slower growing hybrids to languish in poor heavy soil. If possible, position plants on a slope or mound when given this soil condition. Phormium plants suffer from few other maladies. Occasional long tailed mealy bug attacks can be controlled through sprays, and snails that often use the underside of the leaves for an abode can be easily picked off or poisoned.
The most serious complaint we have on the hybrid flax is the tendency of the colorful leaf forms to revert back to a green or bronze color. When a shoot of an unwanted color is seen on a hybrid plant, this shoot should be cut off at the base. With some of the hybrids it is the new foliage that is the showiest, and it is often best to remove all of the older leaves as the new ones emerge. In the individual listings below we have indicated the color forms that are least likely to revert by noting them as "Stable". If diligence is used, even the plants most likely to revert can be kept the original color. It should be noted that not all of the shoots with a different color than the original plant are detrimental; Phormium 'Cream Delight', one of the showiest of all of the cultivars, was a vegetative sport from Phormium 'Tricolor'.
New Zealand Flax is rarely grown for its flowers, as it is the colorful foliage or striking form that is of primary interest. However, Flax will often flower in the garden in late spring or early summer, and are not only showy but also attract nectar seeking birds. The flowers on Phormium tenax and many of the hybrids are orange-red and held upright on a tall stalk above the foliage. Phormium cookianum, and the hybrids more closely aligned with it, have greenish-yellow flowers that are held horizontally on an arching flower stalk. The fruit that follows is also quite different: P. tenax has its woody bean-like fruit held upright and P. cookianum has twisted dangling fruit. The flowers and dried fruit of both types are useful in large flower arrangements.
Sun and Shade
Most prefer full sun but will grow in almost full shade. The colour of the variegated cultivars may fade in heavy shade.
Phormium will grow and thrive in exposed positions. They respond to the wind blowing through their leaves and are
tolerant of wind that is salt laden. They are equally as happy in a sheltered corner of a small garden.
The range of soil conditions that phormium will tolerate is wide. They establish best and prefer growing in open,
free-draining soils but will grow in poorer soils inclusing straight clay. They are often gorn in difficult conditions such
as exposed banks and although they grow in these circumstances, they thrive better when growing in more open soils.
Phormium are easy to grow and can survive in postions with low fertility. However, to get the best from the
plants, especially the variegated cultivars, and to maintain good colour and growth, they require good fertility
evels, especially nitrogen. With the variegated cultivars, the new growth often has the brightest colours.
We reccomend slow release fertliser, every six months.