The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
American Rock Gardens
Top left.—Spring Star-flower, Triteleia uniflora. Top right.—
White ' Twinleaf Squill, Scilla hifoha alba. Bottom left.—
Showy Crocus, Crocus speciosus. Bottom right.—Lady Tulip,
Tulipa clusiana
PLATE IV—SMALL BULBS
Top.—Dwarf Bilberry, *Vaccininm caespitosum. Bottom.—
Diapensia, *Diapensia lapponka
PLATE V.—ALPINE SHRI BS IN NATURE ON MT. WASHINGTON
This must be foreseen and prevented by the laying of the stones. Some of the valleys should have deeper hollows to hold rain for a time, for such rock plants as Primroses and Gentians like their roots well watered. Actual watering of a rock garden is rarely needed, for with correct construction and proper planting the vegetation will withstand any normal dry season. Subirrigation is possible, and at time of construction perforated water pipe or porous drain tiles may be laid among the rocks, about a foot below the finished surface, the upper end to be connected to the water supply for an hour or more in extreme dry weather.
By the time that a few feet of finished rock face have been laid the need of walks for access and circulation will be obvious. Theoretically, in a rock garden the careful visitor may leap from rock to rock anywhere and observe every plant at close hand, but since every good garden is open to crowds of visitors at the height of its flowering season, walks must be provided far out of scale to the needs for caring for the plants and the size of the artificial hillside. Where the walking is greatest and the slope steep, it is best to lay down flat stones, often quickly using the available supply of flattened rocks. Minor walks may be surfaced with sand, peat, or pine needles, to be covered by creeping plants like Thyme. On sharp slopes rough steps must be laid, not too irregular, and yet avoiding a finished effect. In the joints all kinds of tiny rock plants will be at home. The walks would normally follow the valleys, but at times run along the ridges. It is a nice problem to give easy walking service to visitors, access to all plants, and yet make an arrangement pleasing to the eye and not too much unlike natural trails.
