Sempervivum calcareum Sempervivum calcareum Sempervivum calcareum (houseleek) £3.75 Out of stock. 0 in your basket View Basket Checkout Sempervivum calcareum is an attractive succulent with medium rosettes of bright green leaves tipped with a maroon red. Pink starry flowers may be produced in summer. When flowering the height is about 10-15cm, and the rosettes can form a mat spreading to about 20 - 30cm. Grow in a sunny position in well drained soil. Suitable for alpine containers, troughs, rock gardens, scree beds, crevice garden, alpine house.