Light and lacy native tree makes news

Press, 6 May 1983, Page 11

Light and lacy native tree makes news

A new native plant is this week’s exciting horticultural news. It’s not new, exactly, because it has been around since the early 19505, but for

most of that time the problems of propagating it have been unresolved, so it has never become widely known outside specialised collections and botanic gardens. What is it? It’s the var-

legated milktree, Paratropis microphylla “Charles Devonshire.” I have known about it for years, but I had never seen it on sale, until a few days

ago when I (literally) stumbled over a little group of young plants tucked away in a Mid-Canterbury nursery. They had not been grown on the premises, but had come from a large, export-orientated wholesale nursery — so obviously someone has solved the problem of propagating it.

Variegated forms of our native trees and shrubs are not uncommon, but this one is different — its small leaves, grey-green margined creamy white, intricate branching, and habit of building up its growth in cloud-like layers make it one of our most unusual natives.

As an isolated specimen “Charles Devonshire” is not very exciting; its virtue is that when it is surrounded by other foliage its light and lacy texture can enliven the dullest corner — fortunately, it almost demands to be put in a dull corner, because as a forest understorey plant it requires moisture and some shade. It is one of the few shrubs that can safely be planted in a small suburban garden without the fear that it will one day outgrow its welcome, because it is one of the slowest-growing natives; a specimen in the Christchurch Botanic Gardens, a delightful little bush, has been there since May, 1963, but in the two decades has grown barely two metres. It can be seen among the shrubs screening the Cockayne Memorial Garden at the end of the Lime Walk.

The only question that hangs over it concerns its hardiness. The parent tree is well known as an understorey tree on streamsides and forest margins throughout the lowlands, and is quite hardy in any lowland district of New Zealand. Or so the books say. In

fact, hardiness tends to vary from population to population, and some North Island forms of native plants propagated by the large nurseries are not hardy in colder districts; this is the probable reason why some native plants that we regard as unperturbably hardy up to high altitudes in the South Island are considered tender in Britain — the British have North Island forms.

Paratropis “Charles Devonshire” is of subtropical origin; Mr Devonshire found it growing in the bush near Whangarei in 1952.

The Botanic Gardens specimen looks very happy, but it is in a very sheltered spot, and most gardens in Christchurch and on the plains are much frostier. Just in case, I shall keep my plant in its container in shelter until spring, to give it time to acclimatise. It will probably need to be sheltered for its first two or three winters, until it has made sufficient woody growth to survive severe cold.

Astelia “Silver Spear” is another handsome native foliage plant new to my garden. This is hardy (I hope) and one of our most sumptuous herbaceous plants, growing utlitmately two metres or more high, with hube, arching, silver leaves.

It is a selection, or possibly a hybrid, of the Chathams species, Astelia chathamica. Over there it grows in wet, peaty soil, but happily it adapts, like many other natives, to much drier conditions in cultivation.

Imagine a cross between a native flax and the familiar silvery Canterbury astelia, A. nervosa, and you have “Silver Spear.” It will be a problem finding a space for it where its overpowering presence will not dominate the surroundings, but I think I can manage.