Sempervivum tectorum, also called hen and chicks, houseleeks, or roof house leeks, is a low-growing evergreen succulent with red, silver, green or blue-green leaves. From the Latin, "Semper" means always and "vivum" means life. Sempervivum is indeed a plant that seems to live forever. The "hen," a single rosette, produces tiny rosettes, referred to as "chicks." The chicks surround the hen in a tight formation. Each rosette flowers only once and then dies.
Plant Sempervivum tectorum outside in sun to partial shade. These specimens are perfect for rock gardens or sandy banks. An excellent growing medium for Sempervivum consists of 1/3 soil, 1/3 pumice, and 1/3 sand. The most important factor with this succulent is drainage. The soil must be well-drained to prevent root rot.
Place rosettes 10 to 12 inches apart to leave room for the chicks to grow. Water when you plant or transplant a Sempervivum tectorum, then do not water again for five to seven days.
Replace the rosettes after they flower, which they will do in about three years. The plant will send up a flower stalk and produce purplish to reddish-pink flowers, usually in midsummer. Once it has flowered, the rosette will die. In the wild, this would eventually result in a 12- to 18-inch ring of live Sempervivum tectorum around a circle of dead rosettes. To avoid this, dig out the rosettes after they die. Plant a new rosette in the space, or wait for baby plants to fill in the space.
Water Sempervivum tectorum rarely -- remember, it is a succulent, a desert plant. Sempervivum tectorum will grow on its own as long as you avoid overwatering and overfertilizing (fertilise with a quality cactus fertiliser in early spring). The plant is hardy in U.S. Department of Agriculture hardiness zones 3 through 8.
Prevent crown rot and the fungus Endophyllum rust by not overwatering.