Sempervivum arachnoideum is a sure-fire way to excite any visitor to the garden. Just look at the gorgeous blooms! The pale green rosettes are covered with very fine webbing that looks just like cobwebs. In their native habitat this traps moisture and helps them to survive in dry conditions. The small pink flowers are produced in early summer. It can be grown outside in very dry spots but is best grown in pots of free-draining compost. It’s an excellent choice for a rock garden.