Autumn time for discovery

Press, 13 April 1984, Page 18

Autumn time for discovery

One of the nicest things about the garden at this time of year is that as the autumn clean-up begins and vigorous summer growth begins to die back, numerous “forgotten” plants can be rediscovered. Saxifraga fortune!, for example, is a very pleasant sight to encounter in a dim corner of the garden about now. It is one of the odd men out in this predominantly alpine and sun-loving genus. Unlike its rupestral cousins, Saxifraga fortunei is a ■ woodlander which thrives in shade, even quite deep shade, and will not grow unless it is cool at the roots. Throughout the growing season it is attractive. The large leaves, shaped like a heart which has been pressed firmly top and bottom, are leathery and almost succulent in appearance, and bruise easily. On top the colour is forest green with a dash of black; the undersides are beetroot red. The flowers, which appear in large sprays in March and April, are of spidery construction and have a rather lop-eared appearance as a result of the fact that the lowermost pe- t tai is much longer than the

others and is slightly twisted to one side. But they are attractive, and the colour is startling: a pure, glistening white. Few flowers are so pure a white. Saxifraga fortunei is an Asiatic saxifrage, and its name commemorates Robert Fortune, the noted plant hunter who collected in China for Kew Gardens and for the British East India company. It is very hardy, though appearances can be deceptive: at the first hard frost of autumn, sometimes even before the flowers have finished, the whole visible part of the plant collapses into a black pulp. This involuntary sudden dormancy may appear to be terribly damaging to the plant, but in fact it doesn’t do any harm at all. New shoots always appear in mid to late spring, so long as the clump is left undisturbed. To dig it up or attempt to divide it during this dormant period is a recipe for death. Another pleasant sight, revealed the other day when I pulled away the spent flowering stems of one of the “evening primroses,” was a bunch of bright tips on the pretty hybrid heath, “Irish Lemon”.

Gardener’s S DIARY

Derrick Rooney

This little shrub was discovered growing wild in Ireland about 12 years ago by the British historianbotanist, David McClintock, and has been available from some nurseries in the last three or four years. Its botanical name is Erica X praegeri “Irish Lemon,” and it is a result of a chance cross between the “crossleaved heath,” Erica tetralix, and one of the Irish heaths, Erica mackaiana. The foliage of “Irish Lemon” closely resembles that of Erica tetralix, but the habit is that of the other parent. Growth is dense and bushy, on numerous branches which begin horizontally but quickly bend upward.

When there is new growth on the plant all the tips are bright lemon yellow, and in spring almost the whole plant is coloured yellow.. Curiously, however, Mr McClintock discovered this quality only after cuttings

from the original wild plant were growing in his garden; he had selected it for its large, rosy pink bellflowers.

With its neat habit and height which rarely exceeds 20cm, “Irish Lemon” is an excellent shrub for the rock garden, where it needs a cool but open site and copious watering in summer. Another alpine shrub of high garden merit, but from our Antipodean side of the world, is Callistemon sieberi, the Tasmanian mountain bottlebrush. With its small, needle-shaped leaves and erect, bushy habit, this could be taken at first glance for one of the tree heaths, but it actually belongs to the myrtle family, and is thus related to our rata and manuka.

I planted this bush several years ago in a slot near a fence which was the only available site at the time, but subsequent changes in the garden and further plantings to provide privacy resulted in its being submerged. Last year I took cuttings, so that I would have a healthy young plant to establish in a more visible part of the garden. The original is still very much alive, I discovered this week when I fought my way

through the undergrowth to collect seed capsules from its flowering of 1982 (they take two seasons to ripen). Not many gardeners know this bottlebrush, and few nurseries stock it; its charms are a bit too quiet for those brought up on a diet of petunias and marigolds. But I like it. The flowers are in scale with the leaves, and are a greeny-yellowy lemon shade, the kind of colour often described as a “flower arranger’s dream.” Even more delectable, if you can get it true to name, is Callistemon viridiflorus, which also comes from Tasmania. This is more your everyday bottlebrush in appearance, but the short ellipic leaves are of hard texture, with pungent tips. The brushes are a stunning lime green. Like Callistemon sieberi, C. viridiflorus is slow growing, but ultimately it is quite a bit bigger, — I have seen mature specimens three metres or more high. Both these species may be raised from seed, which usually comes true, or from ripe cuttings of short side shoots taken in late autumn or early winter. Seedlings may be expected to flower in three to five years, cut-

ting-grown plants in two to three.

For lovers of green flowers there is another callistemon, c. pinifolius, whose brushes can be a lovely creamy-green shade, but are rather more sparsely put together and look as if they have already been through a good few hundred bottles. I like it, but it doesn’t appeal to everybody. Callistemon pinifolius gets its name from its foliage, which is longer and much stiffer than that of the soft-to-the-touch C. sieberi, though it doesn't much resemble that of pines as we know them. Like the other two, it is slow growing, at least while young. On maturity, when grown in the open, it can make a large, dome-shaped bush a couple of metres high and more across.

Propagation of this unique bottlebrush is a problem for the home gardener. Ripe cuttings do not strike as readily as do those of the others.

Seedlings may be raised from the abundance of seed that the bush sets, but this is not a sure-fire way of perpetuating the unique col- .. our, forms with red flowers •> are known.