Phormium tenax Yellow Wave - New Zealand Flax

Phormium tenax 'Yellow Wave', forming a large dense clump with a slightly spreading and disheleved habit, surprises with the brightness and size of its foliage which uniquely dresses a bed or terrace, becoming the centrepiece. Its leaves, wide, linear, slightly arched, resemble long ribbons of soft yellow satin with long green stripes. This wonderful variety is unfortunately not very hardy. It prefers mild climates and non-calcareous soils from the Atlantic coast to the Mediterranean, which is too dry in summer. It will also thrive in a large container, to be overwintered in a cool climate.

Phormium tenax 'Yellow Wave' belongs to the Agave family. It is a horticultural cultivar derived from Phormium tenax, the larger of the two New Zealand species. This superb rhizomatous perennial grows in a large, non-invasive clump. It has an upright and arching habit, reaching about 1.5m (4ft 11in) in height and 1m (3ft 4in) in width at maturity, quite rapidly, depending on the growing conditions. The leaves are very wide (10cm (3.9in)), linear, arched, very long, quite flexible, and pointed at their tips, remarkably variegated. Their colour, varying from one to another, is a light green-yellow to cream-yellow, irregularly but invariably crossed and widely edged with lines of medium green, from the base to the tip. While the foliage is the main asset of this perennial, its flowering, when it occurs, is not to be ignored. Thick flowering stems, at least 2m (6ft 7in) tall, appear from May to July, depending on the climate, overhanging the clump of foliage. They are green tinged with purple, in the form of curved flower spikes, 5cm (2in) long, which turn a matte red colour when ripe. This flowering attracts certain birds and numerous pollinating insects.

This Phormium is a plant of great ornamental value, suitable for large beds or rock gardens in mild climates. It can sometimes be disappointing in a Mediterranean climate, which is too dry, as well as in overly calcareous soil, but it is magnificent in temperate maritime climates. Used as a specimen or planted in groups, it structures the space and gives a completely exotic charm to the garden. Like tall grasses, it is also a wonderful perennial for a modern garden with clean lines, adorned with bamboo. In cold regions, it can be planted in a very large wooden pot or, why not, in raw concrete, on the terrace or balcony. Its elegance can be admired during the beautiful season, without forgetting to overwinter it frost-free, in a cold greenhouse or a minimally heated conservatory. In an urban garden, it softens concrete structures and is enhanced by a gravel mulch. In a more classic setting, colourful Cordylines and evergreen shrubs with purple foliage, such as Pittosporum 'Tom Thumb' or Lophomyrtus 'Magic Dragon', will form a beautiful backdrop for its luminous foliage.

The Maoris use Phormiums as we use linen, for their fibres which are used in the textile industry. This ability probably explains their vernacular name of 'New Zealand Flax' or 'Mountain Flax'.