HOW TO GROW SUN ROSE
Looking for summer colour? Don’t overlook helianthemums, says Anne Swithinbank
Great for narrow borders, says Anne Swithinbank
SPANGLED with masses of rounded flowers in early summer, the lowly sun roses – or helianthemums – deserve closer inspection.
Blooms usually 1in (2.5cm) across are made of five thin petals with the fragile quality of slightly crinkled tissue paper.
There are over 100 species of these ground-hugging, mainly evergreen shrubs but in gardens we mostly grow the hybrids, usually involving European Helianthemum nummularium,a British native, and the Mediterranean Helianthemum apenninum.
Sun rose and rock rose are common names shared with their slightly larger cousins, the cistus, and both belong in the family Cistaceae. I tend to call cistus rock rose and as the sun is literally in their name, prefer sun rose for helianthemum.
Anyone hoping to fill a narrow sunny border, bank, rock or dry gravel garden on a budget will be glad to make their acquaintance. Seek out small plants in 3.5in (9cm) pots at the garden centre, or buy them mail order, and within a year or two each will spread to 12in (30cm) with a height of 8-12in (20-30cm).
In the wild, sun roses are found in scrub or alpine meadows and could be used in a cultivated ‘meadow’ among weak grasses. These plants revel in bright sunshine, enjoy a light, welldrained soil and, once established, are usefully drought tolerant.
Little maintenance is required other than weeding between young plants while they grow and knit together. Some varieties bear double blooms but for me the simplicity of singles is hard to beat. When not in bloom, the mat of small, often silvery or grey-green leaves makes a dense and attractive, weed-smothering mass.
To see common yellow-flowered sun rose H. nummularium growing wild in the UK requires some effort as they’re specific to calcareous downs, cliffs and hillsides. They love the chalk grasslands of Wiltshire, Cheddar cliffs in Somerset and the limestone pastures in Yorkshire.