Gardening Articles by Russell Fransham
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New Zealand Flax
New Zealand is home to some of the world’s most spectacular grasses.
Phormium tenax is the huge swamp flax found throughout NZ which grows to over 2m high, and Phormium cookianum, the mountain flax, is about half that height and needs good drainage to thrive, although its not by any means restricted to mountains.
Flax is a silly name for this plant really. It arose because British immigrants to NZ realised the fibre of Phormium leaves resembled linen fibre which comes from the unrelated European flax plant, Linum, whose seeds also produce linseed oil.
No doubt the NZ flax fibre industry in the nineteenth century benefited by marketing the fibre under the same name.
Harakeke sounds much nicer.
Their extreme toughness in the wind makes them extraordinarily useful landscape plants and they have become deservedly the most popular nursery plant in NZ. They are enormously popular garden plants throughout the warmer parts of Europe and North America where they are prized as dramatic subtropical plants.
Flaxes have an interesting habit of producing colourful mutations and these have been crossed repeatedly to create some beautiful garden varieties. While swamp flax mutates readily to a reddish brown colour, the smaller, floppier mountain flax crossed with its big strappy cousin has come up with many richly coloured hybrids, the best of which is “Dark Delight”, a stately 1.5m black-purple flax with drooping, shiny leaves and a surprisingly slow growth-rate. It seems immune to any of the diseases or pest damage that afflicts most other flaxes to some degree.
Wild swamp flax though, is really a bit of a monster in a suburban garden because it gets so big and needs lots of rather strenuous grooming to look its best.
Guy Bowden of Tawapou Coastal Natives Nursery near Matapouri Bay has come up with a stunning deep red-purple variety he has called “Stormy Port”. It will be released next year for sale, and is one of the most beautiful flaxes I’ve ever seen. It will be worth the wait.
Yellow flaxes can look lovely in the first year but they tend to be prone to fungal spotting and rots, which show up rather messily on the pale leaves.
The wild form of Phormium cookianum is a soft lettuce-green with graceful drooping leaves and yellow flowers in September. The seed pods hang like spirally twisted green beans, unlike the upright black fingers of the swamp flax pods.
A very wide-leafed cookianum variety found on Mayor Island (Turua) off the Coromandel peninsula has been named “Turua” and is especially handsome.
Flaxes are very easy to grow here but they must be in full sun to look their best. In shade they soon become lanky, sparse and pale. The soil for cookianum types must be well-drained and loose, but the swamp flax is much less fussy.
Annual grooming by pulling off dead leaves one at a time keeps the plant looking fresh and vibrant as the dead leaf bases provide a breeding-ground for fungal rots, mealy bugs and flax slugs, those beautiful, amber, leaf-shaped slugs that cut oblong slits in flax leaves.
Flaxes are such a great feature in any garden because they provide strong contrast in texture, form and colour with almost all other plants especially when massed in blocks of a single colour.
Its hard to imagine a more dramatic and colourful planting for the entrance to Whangarei City Centre than the roundabout at the bottom of Bank street with its massed “Jester” and “Platt’s Black” flaxes.
(Text and photography copyright Russell Fransham 2005)