Gardeners do need to be flexible workers

Press, 10 January 1986, Page 11

Gardeners do need to be flexible workers

GARDENING

by

M.Lusty

The Rosaceae is a very large and cosmopolitan family which has provided many garden plants — crowned, of course, by the roses themselves — as well as fruits such as apples, plums, pears, apricots and peaches. So it’s surprising that it does not figure, except as a very minor component, in the New Zealand flora. But there are a few members of the family here, and although they are not among the “showiest” members of our flora, a few

were looking good this week.

Potentilla is represented in New Zealand by one species. This world-wide genus includes a wide variety of shrubs (all now grouped together in the single large species, Potentilla fruticosa) and about 300, maybe more, herbaceous species, which reach their highest development in the Himalayas and the Far East.

The New Zealand representative is P. anserinoides, which occurs in scattered localities throughout the country and is an excellent ground-cover plant for the native rock garden. Of prostrate habit, spreading by runners, sometimes above ground in the manner of strawberries and sometimes just below ground, it has pretty, choco-late-coloured, ferny leaves and bright yellow flowers. In the wild it grows mostly in damp places at the edge of scrub, streamsides, and on lake shores — including several high-coun-try fishing lakes. But in the garden it thrives, sometimes only too well, in ordinary soil, and stands quite dry conditions.

The New Zealand potentilla is good groundcover for shade, where its foliage is more lush, at the expense of flowers. If you want lots of flowers you have to grow it in full sun.

The genus rosa itself is not represented in New Zealand, if you disregard the sweetbriar and related species which are so widely naturalised they might as well be regarded, now, as native.

Apart from the solitary potentilla the family is represented by a few alpine geums, among which G. uninorum, with large white flowers, would be a choice rock-garden plant were it not a martyr to aphids; by the various bush-lawyer vines; and by the acaenifc or bidybids.

The latter include some rampant weeds, and for that reason are not much grown in gardens, though several species and hybrids have the potential to be excellent and ornamental carpeters for rock gardens or borders. People are put off, I fear, by the barbed fruit of some species which cling to socks, clothing, bootlaces, or the fleeces of passing animals.

Acaena novae-zelandiae, with green leaves, is probably the most annoying of the native species, but it is not as bad as A. ovina, the Australian “sheep’s burr,” which fruits on knee-high stems and makes summer tramping unpleasant wherever it is naturalised.

Worth considering for the garden are Acaena buchanani, from Central Otago, blue leaves and stemless fruit; A. inermis, widespread in the Canterbury high country, with brownish olive or purple (but never green) leaves and unarmed fruits; A. profun-dae-incisa, worth growing for the name alone, even if it weren’t an attractive mat of shaggy green leaves turning reddish in full sun (a north-west Nelson form has silver leaves); A. Fissistipula, an alpine carpeter with near-violet leaves; A. saccaticupula, a high alpine with bright red heads; and A. glabra, a plant of fine, semi-stable screes, with glossy green leaves. A treasure in the genus is A. microphylla var. pauciglochidiata, from Southland and Stewart Island.

A tiny plant, hardly as big as its name, this has very small green leaves edged

with prominent black teeth. On a bigger scale is A. anserinifolia; the mainland form is a vigorous weed, but a form from Campbell Island is in cultivation and has lovely silvery leaves. This species figures in the parentage of some of the hybrids which are highly regarded overseas for their large, red heads.

I have one from the CroestfSP Mountains which has most attractive foliage,

with an olive tinge, and hugs the ground closely. The Kt had bright red heads ly seedling has not yet flowered.

All these bidybids are, I think, most easily managed as young plants, say up to about four years Old. As they all strike quite readily from cuttings in late summer or autumn, or rooted pieces in the spring, it is not difficult to keejirup a supply of replacements.