Gardening Articles by Russell Fransham
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Mat Rushes, Lomandra
New Zealand's Native tussocks and grasses are beautiful in all their variety of colour and form, and mass-planted they can be a wonderful sight.
But I've reluctantly stopped planting most of them because I hate the way they start to randomly rot and die after the first few months. Not a good look.
We have to recognise that most of them come from cool, alpine climates with very low humidity most of the year and loose, gravelly soils. Here in the Northern North Island we have warm, humid conditions and generally richer, stickier soils, and when its wet they can't handle it.
This is where the Aussies come in.
The Mat Rushes, Lomandra, are a family of 50 species of handsome Australian grasses.
Well actually they're not grasses. They just look like grasses.
They're closely related to the amazing grass trees, Xanthorrhoea or 'Black Boy'.
Many of them love our humidity, thrive in full sun or partial shade and being Australian, can handle extreme drought and frost, heat, fire and even sticky hard clay.
The Spring flower heads of all the Lomandras are interesting spiky affairs with masses of creamy yellow tiny flowers among the soft spikes.
As the flower heads dry out they retain their unique form which makes them useful for floral art.
Lomandras are dioecious, which means the sexes are on separate plants, and the flowers are, of course slightly different from each other. The boys look a bit more sort of, well frilly, while the girls are a mass of business with no major fluffy bits. (Yes I did study botany at university and my teachers have all mercifully passed on, hopefully not because of me).
Lomandra longifolia, the spiny-headed mat rush, is one of the biggest and is about a metre high with strappy, leathery leaves a centimetre wide which can be used to weave mats. The leaf tips are strangely notched to form two uneven points and this is a characteristic of all types of Lomandra. Its extreme toughness means it grows well on the coast, making a handsome flax-like clump that thrives in the wildest conditions. You often see it used in parks and traffic islands in Sydney and Melbourne, a testament to its extraordinary hardiness. Another very different form of Lomandra longifolia, known as "Tanika" is a much smaller, finer version which grows to about 60cm, with deep green, glossy tussock-like leaves and makes an outstanding substitute tussock for our humid, richer conditions. It looks remarkably like Carex secta but handles very dry as well as wet soils. Its brilliant green foliage seems to last for years without developing brown, dead thatch like most other tussocks.
Lomandra hystrix is another beautiful big flax-like plant like the common form of L. longifolia, although it is a brighter green, less glaucous than longifolia and the large flower heads stand a metre high with a more feathery appearance. L. hystrix is found in estuarine margins where brackish water and prolonged waterlogging occurs but it also grows well in dry conditions. This one makes a spectacular septic transpiration-field plant where it can reach 1.2m or more and moves beautifully in the wind.
Lomandra confertifolia 'Little Pal' is about 50cm high with very shiny green, fine leaves that move sinuously in the wind and never seem to get tatty. Mass planted, this one is a superb sight, especially teamed with pink or bronze flaxes or with purple-red coloured shrubs such as Loropetalum 'China Pink' or the outstanding ground-cover Grevillea 'Bronze Rambler'. "Little Pal" seems less tolerant of hard clays and wet conditions, preferring loose or sandy light soils.
A dwarf form of Lomandra confertifolia, called 'Little Con' is a compact, ball-shaped spiky mound which makes a handsome lime green groundcover to contrast with darker foliaged shrubs.
I have found Lomandras effective for stopping erosion of soil through gaps between rocks as the fine roots bind loose soil very effectively.
They make a great border planting beside paths or driveways, preventing spillage of bark or soil onto the pavement while looking lush and well-groomed all year.
They would also be perfect to plant on evapo-transpiration fields for modern septic tank systems and their grassy form would blend seamlessly into an otherwise native garden. I have grown all these for many years and found no evidence of weediness or any potential threat by self-seeding. I do notice sparrows and goldfinches feeding on the seedheads through Autumn.
These Aussie battlers are becoming increasingly popular in Northern NZ gardens as gardeners become disillusioned with the native alpine tussocks which are so unsuited to our climate. If you're a frustrated tussock-lover, why not check out these Aussies. They could almost pass themselves off as locals.