The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Rockweler Rockgardens
Soils And Fertilizers For Rock Plants
THERE is probably no question connected with rock gardening which is more of a bugaboo to the beginner than that of providing suitable soil, or soils, for the little friends whom he has invited into his garden and intends to do his best to make happy. To read some of the works on this subject, the layman may easily get the impression that it is really necessary to provide each individual plant with a soil made up according to a special prescription! Nowhere in the whole broad field of gardening is "debunking" required more than here.
WHAT THE ROCK GARDEN SOIL SHOULD PROVIDE
The secret of success with rock plants, so far as soil is concerned, is the old, old one of going back to nature and of taking a look at what she herself provides them with.
Drainage. If you climb up a rocky mountain slope to the timber-line, to the bleak and native haunt of the alpines, or search out most of the other rock plants and find where they row as wildlings, the most apparent characteristic of the soils in which they grow is plainly to be discerned—it is exceptionally excellent drainage. Drainage not of the subsoil—as we usually speak of it in connection with flower garden, orchard, or field—but quick and complete drainage of the surface. Often the clumps of leaves of the little plant, hugging the ground closely as they must to preserve an existence, rest directly upon shale, gravel, or splinters of rocks. And so our first consideration in supplying a man-made soil for this class of plants should be porosity, assuring not only good drainage as we ordinarily use the term, but the immediate escape of all surplus water to the lower soil levels.
Moisture. If, however, you attempt to pull up one of these tiny, and possibly rather frail-looking, denizens of the plant world, you get a sharp surprise. It is simply anchored fast, and will require much more effort to dislodge it than would many plants in your garden ten times its size. In fact, if you could succeed in getting it out, roots and all—which would be extremely difficult—the most conspicuous thing about it would be the extreme length of the roots in proportion to the top. And if you could follow to where the roots penetrate, you would discover an unsuspected degree of moisture in the stonefilled soil; for stones, in spite of their dry appearance, are among the most efficacious of moisture conservers.
