DUNEDIN GARDENING CLUB

Otago Daily Times, Issue 22398, 20 October 1934, Page 3

DUNEDIN GARDENING CLUB

CULTIVATION OF ALPINES ADDRESS BY MR D.' LEIGH. The fortnightly meeting of the ' Dunedin Gardening Club was held on Tuesday evening, when Mr J. Passmore presided over a good attendance of members. The lecturer was Mr D. Leigh, of the Botanic Gardens, who gave an address on “Alpines and Their Cultivation,” and by the use of lantern slides showed some fine examples of alpine plants as well as views of rockeries in the Hew Gardens and in private gardens in England. In the course of his remarks, Mr Leigh said that no part of the garden could claim to give such a continual source of interest as a well-planned and carefully planted rock garden, to give the plants grown in it conditions similar to those existing in their natural haunts, and to provide each plant with its own individual requirements. The culture of rare and difficult alpines was an absorbing study, and success in their culture was attained either by endless experiment or by a wide knowledge of their environmental conditions in the alpine meadows and among the rocky debris fed by the snow water from the frozen summits. _ It demanded enthusiasm, especially if one started to collect species of a genera such as Saxafragacae, a huge race and the backbone of the rock garden, the members of which developed needs and characteristics so diverse that the gemm for .the sake of convenience had. been divided into 17 very different sections. Very few rockeries were what they should be in design and beauty;. the failure was not as some imagined, entirely attributed to either ignorance of things beautiful or to lack of imagination.. Possibly the fault lay most frequently in the lack of observance of those natural laws to which an alpine rockery should be subject—to represent Nature as a whole, and in the smallest detail. The conditions in and about Dunedin could not be surpassed for growing alpines. The possibilities were, greater than in most parts of Great Britain, as numerous plants, not hardy in the Home country, could be readily grown here. Not only that, but there were the hundreds of beautiful plants from the New Zealand Alps that were worthy of the foremost part of the rock garden. The ideal rockery should be a mountain in miniature, and therefore the nearer it approached a mountain m features the nearer it would be in perfection. The perfect rockery should have gorges leading to passes and othei parts of the mountain, one of them ending in a cirque. There should be flat, rocky plains with profound crevasses in which ferns could be planted. There should be a moraine, with large and small stones strewn along its bed. The moraine was the most modern addition to the garden of to-day. A great feature should be the mountain meadow, boulder strewn and made up with fine fesque grass, planted with such as the Aquilegia glandulosa, Viola gracilis, Geranium sanguineum, Narcissus bulbocodium, and other alpine bulbs. There should be scree slopes—arid expanses for such plants as the Kabschia Saxifrages, Drabas, and Androsaces. These different formations gave an excellent variety of planting places. In so many rock gardens there was such a distressing similarity in available planting sites. . Explaining the construction of the rooK garden, Mr Leigh said that the first thing to do was to see that the ground was well drained. If one had to contend with a clayey subsoil he must invariably excavate the clay to a foot or 18 inches below the rockery and for a small margin' all round. Good drainage must be incorporated next. It was then necessary to get an outline of the formation of the site forming the higher pop tions. especially the centre portion, for it wag here that the heavier stones must be placed/ The central core of the mound should never be impermeable old soil or dumped rubbish. The soil composts should be prepared and ready for working in along with building operations. The main bulk of the soil should be made up of good fibrous loam, with well-rooted leafmould and plenty of coarse sand, screenings, and granite chips, or what are usually called toppings. The most interesting part of the work was the placing of the stones. In, say, four places chosen for height or as an indication of the fall, what might be called the “ keystones,” should be placed. In the placing of these keystones lay the whole secret for success. The actual building of the rockery should be firm and solid. If the stone that was used was small, then half of it should be buried beneath the surface and the other half used up so as to give elevation. Small stone was useless for rockery construction and should only be employed in the construction of moraines. With large boulders one could get quick elevation, the appearance was better, and there was not a hopeless, out-of-date assemblage of what were termed “pockets.” The construction of pockets had been the cause of the distressing similarity of available planting sites. Long drifts of soil at different elevations and in different aspects were much more desirable. Here and there there should be a craggy eminence over which the plumes of Saxifraga longifolia might be hung, and beneath this a scree slope where others might make matted cushions. »

The more numerous the different planting sites were the greater would be the interest. It was the whole art of building an alpine rockery to create as many different planting sites as possible. On the motion of Mr C. Rhodes, Mr Leigh was accorded a hearty vote of thanks for his instructive and interesting address. Mr Simpson was in charge of the lantern.

An invitation was received from the Oamaru Borough Council for members to visit the Oamaru Botanic Gardens on Laboour Day.—The secretary was , instructed to make the necessary arrangements.

There were on exhibition some excellent examples of sebizanthus by Mr Passmore and various cut flowers by different members.