Sempervivum

Houseleek
Crassulaceae
Cacti and succulents, Perennials

Native to the mountains of Europe. Form tightly packed rosettes of fleshy, evergreen leaves; spread by little offsets that cluster around parent rosette. Clustered, starshaped summer flowers in white, yellowish, pink, red, or greenish; pretty in detail but not showy. Blooming rosettes die after setting seed, but offsets (easily detached and replanted) carry on.Many species, all good in rock gardens, pots, even in pockets in boulders or pieces of porous rock. Need excellent drainage. Water only to prevent shriveling. Protect from full sun in hot desert regions.

Sempervivum arachnoideum

Gray-green rosettes of many leaves are joined by fine hairs for a cobweb-covered look. Larger rosettes (to 3 in.wide) are surrounded by host of smallerrosettes. Spreads slowly to make dense mat to 1 ft. or wider. Bright red flowers on 4–6-in. stems.

Sempervivum tectorum

Gray-green, 2–5-in.-wide rosettes spread quickly to form clumps to 2 ft. or wider. Leaves have red-brown, bristly tips. Red or reddish blossoms are borne on stems to 2 ft. tall. Colored-leaf varieties in red, purple, chartreuse, and silvery blue are available.