Rock gardening is gaining each year in popularity, at least here in the Northeast. If you have not tried one, plan to do so, especially if part of your property is sloping. Many wild flowers, which have of recent years been offered by nurserymen and seedmen, have adapted themselves readily to the rock garden, for it is on rocky hillsides or mountains that some botanists first discovered them.
Assuming that you have your rockery - what to put in it? Here is where so many amateur rock gardeners are so unwise. They either fill the rockery so full of dwarf evergreens that there is little room left for lovely moss effects of spring matting plants or small bulbs; or they fail to use real rock-garden plants for spring-to-fall rotation, depending for color on masses of summer and fall annuals, petunias, dwarf marigolds, etc., often too tall. Having taken all the trouble to make a rockery they fail to use it as such.
I am, therefore, out of my own experience and from my observations of really beautiful
landscaping rocks and rockeries of other gardeners, suggesting some plants for a succession of color from spring to fall, in sunny or shady locations. Spring is the principal season in rock-garden bloom; so the spring perennials are "musts,"
My first suggestion then is Arabis Alpina, It blooms here most of April and on into May, masses of white flowers like small white violets, about six inches high. Variety "Compacta" is lower, more dense, still better for the rockery. A rose-tinted variety, "Arabis Alpina Rosea" has a delicate staining of rosy pink, like "sunrise on snow" (to quote seedman, Rex Pearce).
Arabis likes sun, but will do well in light shade. Grow masses of it close to a large rock under which it can send its long roots. It's small seeds grow in long pods above the leaves. These pods retain the seed even after fully ripening. I simply cut off the brown seed pods and broadcast them in a flat of light sandy soil, rubbing the pods together between my palms, not attempting to extract the seed from the pods. I do not cover with soil, simply water well with a fin-i spray. Transplant seedlings to a permanent place in the rock garden in early fall. In this way you will soon have the necessary massing of bloom to make an effective display. Try Arabis.
