Sedum is a genus of deciduous or evergreen perennial in family Crassulaceae, comprising 400 species of leaf succulents. It is commonly known as Stonecrop and can be found throughout the Northern Hemisphere.
Many Sedum species are grown as garden plants, due to their interesting and attractive appearances and hardiness. Various species differ in their requirements; some are cold-hardy but do not tolerate heat, some require heat but do not tolerate cold. Sedum species are used as food plants by larvae of some Lepidoptera species including Grey Chi. The endangered San Bruno elfin butterfly of San Mateo county, California, feeds exclusively on Sedum spathifolium.
Smaller forms of Sedum are grown in rock or scree gardens or in alpine houses, while larger forms can be grown at the front of mixed borders. Sedum can also be used to provide a roof covering in green roofs. They are preferred to grass for green roofs.
One of the best Sedum is Sedum spectabile (Ice plant), 45 cm high and across, which produces rosettes of fleshy, grey-green, deciduous leaves. On warm sunny days in late summer and autumn, the clusters of pink-purple flowers are covered with bees and butterflies.
S. spurium (Caucasian Stonecrop, Dragon's Blood Sedum, Two-row Stonecrop), 10 x 60cm, has reddish stems and toothed, dark green and evergreen leaves. It bears clusters of pink-purple flowers on erect stems in mid- to late summer.
S. lydium (Least Stonecrop), 5 x 20 cm. grows well in cooler, shadier conditions than others in the genus. It has bright green, evergreen leaves and bears clusters of white flowers in early to mid-summer.
Sedum grows well in full sun, in well-drained, neutral to alkaline soil. Propagation is by seed in spring or autumn; and divide in spring. Pests are slugs and snails.