ROCK GARDENS.

Auckland Star, Volume LXVII, Issue 193, 15 August 1936, Page 6

ROCK GARDENS.

BECOMING POPULAR. Rock gardens are becoming a feature about the city of Auckland, and should become more so. The great lava flows from the numerous volcanic cones which dot the familiar isthmus provide exactly the right class of rock and soil for this class of work. The old fences and walls of basalt stones which form so many of our garden walls, distinguish Auckland from any other city in the Dominion. How much more beautiful these innumerable walled gardens and many natural mounds of steep faces of broken rock would be if they were adorned with suitable flowers and plants. The rock garden derives its chief charms because it is possible to grow a greater quantity of varieties of plants on a small space, it can bs weeded and cultivated at any weather except while it is actually raining, individual plants can have their particular soil, or position requirements satisfied, and if the cost of transportation of soil and stone can be met, a rock garden can be built oil any foundation. In many gardens the position lends itself for rock gardens; often there are outcrops of stone that can be used, and the soil is sufficiently good to at least form the base for the majority of the plants. It is essential that the rockery is well drained, even if there is a pond formed at the base—the actual rockery must be well drained. It does not matter what the quality of the surface soil upon which to build or construct the rock work is, provided ample drainage is arranged for. This may easily be done by placing a thick layer of medium scoria upon the original surface. The rockery must be in an open position and free from root encroachment of trees and shrubs. Nothing is so impatient of root encroachment or shade than the general run of alpine or rockery plants. Rock gardens may be so constructed as to assume various forms. Suitable aspects may be provided to suit different plants, and these may bo readily secured in its formation. Formality must as far as possible be avoided. The stoftes should be so arranged as to form cavities and pockets of various sizes.. And, most important of all, ample spaces must be provided in which to grow those varieties of plants that make the best display grouped I together. Even clay banks, where the pood surface soil has been removed, may bo made most attractive by so arranging the stones to form pockets and ample receptacles for an endless variety of plants. The stones must be sufficiently large to permit fairly deep fillings of specially prepared soils, which should not be too light but of sufficient body to enable the plants to flourish and derive enough nourishment for their roots. The clay subsoil keeps the 6oil cool and moist. Rockeries generally improve in appearance with age, and when the plants have had time to fill their allotted spaces. Changes so essential in any garden to add diversity can always be made, and improvements effected where changes are considered necessary if the first arrangement is considered unsatisfactory. An annual top dressing of fresh soil is necessary for those plants that exhaust the soil during the first year. Water taps should be so arranged as to ensure for a plentiful supply of water during dry weather. This is essential to keep the occupants in a flourishing condition. Where space is not limited an endless variety of plants may be grown. Even in a confined area "it is surprising the number of plants that may be accommodated. By arranging the. soil in the various pockets or spaces, such plants as Ericas, Boronias, and others that thrive in specially prepared soils without manure, excepting, perhaps, a light top dressing during the summer months of thoroughly well rotted cow manure, may be grown in close proximity to plants that need rich cultivation, provided the planting is arranged to avoid the mineral properties percolating into those that need no manure. "Various aspects may also be arranged for plants. Those that require full sunshine may be planted to face the north, and those that are hardy and require cooler conditions may be planted on the south side with a southerly aspect. By obtaining suitable stones, pockets and crannies may he made to siiit plants that need but little.sun. Dry conditions may also be had under overhauling stone's that ward off the rains. It is pleasing to note the increased interest that is being taken in rockgardening. The abundant supplies of suitable stones in the areas furnish ample material for this style of gardening. In the planting, special care should be taken to avoid selecting any of those plants that become noxious weeds,