Guest Author - Connie Krochmal
Here are some additional hardy perennial succulents that can be used in and on stone walls.
Several species of this group are suited to stone walls.
Jovibara hirta is native to Europe. This one has prominent, hairy tips on the foliage. The rosettes can reach over 2½ inches in diameter. The flower stems grow to nearly a foot in height. The soft yellow blossoms open in dense, round clusters during mid-summer.
Jovibara sobolifera reaches about seven to eight inches in height. This plant forms neat rosettes in clusters that resemble those of the houseleeks. Native to some parts of Europe, this has pups that are jumbled tightly together, which can make it hard to divide the offsets. The dark green foliage has bristled edges and red tips. Yellowish-green flowers are crowded together in round clusters. These open during the spring. This is the most commonly grown species of Jovibara.
A number of low growing spurges would be suitable for stone walls. However, these can sometimes be quite vigorous and even invasive as they self sow and spread.
Most have gray-green foliage and flower stalks with colorful, long-lasting
flower bracts. The blooms open mostly during the spring and early summer.
Unlike some succulents, the spurges can tolerate partial shade.
Wood spurge is native to Europe. This vigorous plant reaches over 2½ feet in height. During the fall and winter, the foliage that is overwintering becomes darker in color. This has colorful yellow bracts from mid-spring to early summer.
Broad leaved spurge is native to Europe. With beautiful whorls of greenish-gray foliage, this reaches about a foot in height. It is pretty much evergreen except in very windy areas. This can be cut back in early spring before the new growth starts. It blooms in early spring.
Cushion spurge eventually reaches about two feet in height. Forming large clumps, this has foliage that can become bright red during the cooler months. This perennial is noted for its greenish-yellow flower bracts. They open in terminal clusters on tall stems. These appear in late spring to early summer.
Stonecrops or Sedums
Any number of stonecrops or sedums are suitable for stone walls, and will be dealt with in a later article.