from March 1997
Spring fever has come upon us! Our late February warming trend has started to entice gardeners out into their yards, eager to plant. There are many nifty rock garden and perennial plants that will "live long and prosper" in their gardens. Since most rock gardens are in raised beds or troughs and are composed of fast-draining mix, even if there are further heavy spring rains these rock garden plants should thrive.
One of my favorite rock garden gems is Aethionema coridifolium 'Warley Rose' a tightly branched 6" high by 12" wide mound of fine blue-green leaves tipped in spring with clusters of bright pink flowers. Place it in full sun in a position where you can really observe it closely, as the intricacy of leaves and slender branches is lovely all year. Though it is cold hardy, it does not grow well in very hot regions. Give regular, moderate irrigation.
Another small-stature treasure is our own California native, Arabis blepharophylla 'Spring Charm'. This perennial rockcress blooms profusely with sprays of magenta flowers rising to 8" high above tightly clustered rosettes of dark green leaves. It repeat blooms for me if I prune off the old flower spikes before they set seeds. Prefers full sun in a coastal location, partial shade inland, and regular, but moderate water.
Lewisia are classic rock garden plants. Lewisia 'Dark Cloud' is a cross between our native Cliff maids, Lewisia cotyledon howellii, and our most red colored plant of Lewisia 'Sunset Strain', a seed strain initially developed by Jack Drake in Scotland. The leaves form a crown of succulent-like foliage to 8" across, topped by flower stems 6 to 10" high with clusters of electrifying purplish-red colored buds and flowers which rebloom several times a year. Give sharp drainage, gravel around the base of the leaf crowns and water only when dry. On the coast they perform well in full sun to light shade, inland best in partial shade.
Among our sweet smelling violets we have the compact 4-6" tall Viola odorata 'Rosina' with fuzzy leaves and rose-pink flowers. It forms broad clumps of lush green, heart-shaped leaves and will spread slowly by runners. Our little native that is seen from Alaska to Colorado, and from Yosemite to our coast, is Viola adunca. It grows low to the ground forming tight mats to 3" high with many deep purple blossoms with white centers. These appear from spring through summer poking up just above the foliage and you can see them locally atop San Bruno Mountain.