Lesser known flowers offer fresh colours

Press, 29 December 1989, Page 18

Lesser known flowers offer fresh colours

AxrdenerS] W DIARY

Derrick Rooney

The main display from shrub roses — the last major group of early-sum-mer flowers — is over and gardeners who have no dahlias or carnations to fuss over can now take a breather.

The focus of activity in the garden for the next month,, other than for compulsive propagators who will be busy taking cuttings, will be applying or conserving sufficient water to maintain growth until the flush or herbaceous border flowers comes in February. Do riot believe that this means the garden need be deprived of new year colour. Lots of treasures will flower through January — alstroemerias in pinks and yellows, hostas in lilacs and purples, astrantias, spiraeas, campanulas, hebes, etc. These plants are familiar and it is better to draw attention to lesser known new year flowers. Many people grow large-flowered pink or white annual cosmos for cut flowers, but few are aware of the perennial species which come mostly from the highlands of Mexico and other Central American countries.

Black cosmos is the best of. them. Its name is Cosmos atrosanguinea, it grows about 60cm tall, and it has flowers like small, single dahlias. The texture is velvety and the colour deep maroon crimson, accentuated by a ring of golden stamens. The roots reserhble dahlia tubers and, like dahlias, may be propagated by division in spring. They are, however, marginally hardier than dahlias and in most New Zealand gardens there is no need to lift and store them for winter. One more attractive feature of this elegant Central American peren-

nial is that the flowers are sweetly scented of dark chocolate. Eupatorium purpureum, sometimes called Joe Pyeweed, is an autumn-flowering North American perennial with bold heads of small, deep purple flowers on stems as tall as two metres. It is fairly familiar to gardeners. Less well known is E. cannabinum, a European ditchweed. Its English name is hemp agrimony. It loves moist ground, tolerates wet feet and thrives in ordinary border soil, growing 1.5 m or more tall. When it gets into soil it likes, its aggressive, colonising ways can make it a nuisance. But it has something that no other midsummer perennial has: its colour. The heads of small, fluffy flowers are soft bois du rose, lovely with yellow daylilies. The flowers are succeeded by silky silver seedheads, equally decorative. But if left, the seeds soon spread the plant around the garden. I would not disqualify hemp agrimony from the summer garden on this account. It’s only a moment’s work to cut down and discard' the stems just before the seeds ripen. Crepis incana has leaves so closely resembling those of the dande-lion-catsear family that a very clear label is essential to. protect it from weeder’s fingers. Crepis is indeed related to these ? andjts flowers do _. J/- ..—

resemble those of the catsear, albeit in a refined fashion. This is forgiven, though, on account of its colour: limpid orange. There is something especially engaging about garden flowers that are closely related to weeds. One man’s weed, as the saying goes, is another man’s frisson. Hieracium, a notorious weed in this country, includes . a species, H. aurantiacum, which is a garden plant in Britain where, in spite of its unromantic common name (Grim the Collier) it is planted for groundcover. Grim has dark, hairy leaves and orange flowers and is one of the weeds in New Zealand. Another hieracium, which you might see in the Queenstown area, can be a garden plant here. It is named H. subaudum, grows up to 60cm tall, and has bright yellow flowers. Its tight, woody rootstock does not run.

Though perennial, H. subaudum has the habit of shedding most of its leaves before the flowers open, so that if you grow it you need to hide its bare legs with something lower growing. Stachys lanata “Silver Carpet,” a non-flowering clone with very furry, silver-white leaves, does a fine job; if you like you could plant the newer clone, “Cotton Boll,” the flowers of which are hidden in spheres of woolly white hairs.

Do not worry about being invaded by this hieracium. It spreads only by seed, and so if you remember to cut it down as soon as the flowers fade, it will never become one of your weeds. New foliage sprouts from the base after flowering and remans fresh and gregn