Houseleeks or Sempervivum (meaning live for ever) are succulent ornamental hardy plants that have been used in pleasure gardens since around the thirteenth century. Later during the Italian Renaissance these plants were adopted for use in planting schemes as a solid massed groundcover, which also included camomile, mint, tarragon and violets. Related to Sedum, houseleeks have the capacity to survive with very little moisture, making them the ideal plant for those gardeners with little time on their hands for watering. They are mountain plants and used to scraping by clinging to rocks and crevices in boiling hot sunshine. Mainly found throughout southern and central Europe as well as Africa and Asia there are about fifty species and countless variations on these species.
Much of their beauty lies in their variation in size and colour from as tiny as a pea to a larger fleshy rosette shaped leaf up to fifteen centimetres in diameter. The rosettes vary in texture from perfectly smooth wedge shaped leaves to hairy, slightly spiky leaves as well as leaves that are attached with fine silky spider’s web like threads.The colours range from incredible glaucous blue leaves with iridescent pink flowers, through to translucent reds, bright green with red tips, jade green with dark brown tips as well as crimson red with green tips. They generally do not flower until they have grown for about two years, but when they do flower they produce very unusual flowers.
Over time they increase their clumps and can be easily propagated by simply breaking a rosette off at the stem and planting straight into a pot of compost mixed with grit. The very large houseleeks do need more compost in order to survive extreme lack of watering but the smaller varieties will put up with the worst conditions of all.
They are found used as a ground cover in planting schemes, as well as in troughs and bowls. I have seen them used as a seasonal planting in bedding schemes in Parade Gardens in Bath over the years. However, my favourite use for them is in pots and containers or planted into dry-stone walls or any other nook available. They look good planting singly in terracotta pots as an outdoor table plant, or in groups in shallow terracotta saucers. As long as the place you choose to plant them is dry and sunny they will cling on wherever they can. They are also sometimes used in green roof plantings.
A really easy to grow planting combination would be to line a stone trough with some broken pots for drainage and fill with a soil mix compost, I like John Innes compost best, then mix in a teaspoon of slow release plant granules and some extra gravel for further drainage. Plant with a mixture of houseleeks, alpine Phlox, pink Saxifrage, white Saxifrage, some alpine Aquilegia and a white Helianthemum, then cover the remaining surface of soil with more gravel to act as mulch. Keep this in a sunny position and remove any dead flower heads or leaves. This trough should last at least a couple of years before it will need replanting.
This hardy, easy to grown, low maintenance plant is a real winner for sunny gardens, requiring minimal attention but giving a lot back in terms of strong shapes and interesting colours.