Wonder from DOWN UNDER
New Zealand f lax is a real showstopper that will add extra oomph all year round
OSCAR-winning actor Russell Crowe and the All Blacks rugby team are among the best known things that New Zealand has given the world. But as far as I’m concerned, none is as important as another Kiwi export that elevates our gardens with its muscular shape, colourful leaves and forceful presence.
I’m referring to phormiums, a dramatic group of evergreen perennials that are known colloquially as New Zealand flax.
Forming an architectural clump of sword-shaped leaves, these showstoppers will add oomph to gardens all year and are particularly valuable in winter, when there’s little else to turn heads.
Few other plants can compete with their foliage display. Ranging in height from 18in to 12ft, phormiums spread to at least 40in and have leaves in shades of green, bronze and purple. The showiest are decorated with vertical stripes in two or more colours, including cream, yellow, gold, pink and red.
These strident gems have been grown in Britain since the 19th Century but were first mentioned in print in 1776, when a botanical painting and description appeared in a book by Johann Reinhold Forster. The naturalist accompanied Captain James Cook on his second expedition to New Zealand in 1773.
LONG before t hey appeared in gardens, phormiums played an important part in the lives of Maori people. Leaves were woven into mats, clothing and containers, and fibres were extracted for making ropes and fishing nets, while juice from roots was rubbed on to gums to soothe toothache.
There are t wo species of phormium indigenous to New Zealand: P. tenax and P. cookianum. Both have provided plant-breeders with the genes for scores of varieties. The progeny of the first tend to form large clumps of upright, rigid leaves, and those related to the latter are more compact, with arching, floppier foliage.
They may be grown primarily for their foliage but phormiums also have striking summer flowers. P. cookianum varieties produce greenish-yellow flowers held on stalks that rise just above the foliage, while the red blooms of P. tenax are carried on stems that can reach 13ft or more.
All phormiums will prosper in a sunny spot but there are some that are tolerant of lower light levels, such as ‘ Alison Blackman’, ‘Black Velvet’ and ‘Maori Queen’. They will thrive in fertile, moist and well-drained soil – improve clay by working in well-rotted manure.
Hardy down to minus 10C, and with leaves resistant to wind and salt, phormiums will grow without a care in clement parts and will even cope with coastal locations if they enjoy mild winters. In colder areas, give them a sheltered spot to prevent damage from heavy frosts and strong, icy gales.
These bold plants l ook at home in a variety of planting schemes, including Mediterranean-style gardens and traditional mixed borders. In my own garden, Phormium ‘Yellow Wave’ rubs shoulders with Roscoea ‘ Wisley Amethyst’ and Schefflera taiwaniana.
It’s important not to bury the crown of the plant when setting in the ground, so dig a hole that’s the same depth as the rootball and three times as wide. Make sure you take into account its mature size and provide plenty of space, as lower leaves are likely to suffocate any smaller or less robust plants in the immediate vicinity.
Another option i s to raise compact phormiums in large containers of good-quality multipurpose compost with added John Innes.
Start them off in 12in pots and move them into slightly larger ones every couple of years. For an extra dash of summer interest, under-plant with petunias or other trailers.
Keep plants in good shape by removing any dead or dying leaves, as well as those around the base that have become tatty – thin leaves are easy to remove with secateurs but thicker leaves may need to be cut off with a gardening knife.
Remove old flower stems in early spring, cutting as close to the ground as possible.
Stockists include bigplant nursery.co.uk, crocus.co.uk and jacksonsnurseries.co.uk.