Rock roses are a cheery presence, producing mats of bright, jangling colour along sunny border edges and rockeries in many late spring gardens around the country. The wild species Helianthemum nummularium is a British native found on sunny, chalk grassland and upland limestone landscapes in England, but also on more acidic soils in Scotland. It’s a lowgrowing mat or hummockforming shrublet clothed in tiny, narrow, oval leaves. In late spring and early summer it becomes covered in a sheet of small, clear yellow, five-petalled flowers which are highly attractive to bees and other pollinators.
There are a great many hybrids in a wide range of bright and subtle tones, often attractively set against silvery or grey foliage. The ‘Ben’ series often seen was created by John Nicoll, an amateur plant breeder and jute merchant from Monifieth, east Scotland. By the time he died in 1926 he’d produced 17 varieties, each named after a Scottish mountain. A handful of these varieties, including ‘Ben Hope’ and ‘Ben Fhada’, still remain very popular, while others are rarely grown today.
Rock roses love full sun, growing in any well-drained, even poor, soil. After flowering, trim spent shoots back to encourage new growth and cut back the mats if they’re too expansive. Avoid growing them with slower-growing alpines as they’ll soon swamp them. Trimming also keeps rock roses rejuvenated and removes seed pods, preventing self-sown seedlings from invading gaps between paving slabs.