They were once grown on roofs to ward off lightening, and in fact Sempervivum still are today. An ornamental and medicinal herb. A herb with Magical powers of Love, Luck and Protection. Easy-to-grow succulent rock plants in an interesting range. Thick, succulent rosettes of foliage can be used in carpet bedding schemes. Grow in rock gardens, wall crevices, in troughs, containers in scree beds or Alpine houses. Hardy Rockery Perennial. Sempervivum - House Leek