The parent plant, Helianthemum nummularium of which many cultivars have been breed is commonly found situated on chalk down land or in meadows. Plants will grow best if you are able to reproduce the same conditions within your garden including bright sunshine, good ventilation and a well-drained slightly alkaline soil. Depending on the individual cultivar, Helianthemum’s can spread up-to 18inches (48cm) and grow to 12in (30cm) in height. In order to produce plenty of flowers, plants should be regularly pruned to encourage fresh growth.
Plants should be pruned immediately after summer flowering to help keep them neat and long lived encouraging new growth and another later display of blossom.
Flowers commonly have 5 sepals and 5 petals with a centre containing numerous stamens. Each bloom is ephemeral lasting only one day. However, they produce so many buds that each plant will be covered in heavy blooms from May to July. Some of the flowers are bicoloured with a brighter colour centre to attract pollinating insects. It is also common for flowers to fade in colour over a period of time.
The majority of cultivars will tolerate dryness but cannot survive in water logged conditions. Nevertheless, they do need some water on extremely hot, dry days particularly during the hottest days of summer.
During the summer months, the plants can be covered with bees and butterflies as Helianthemum’s provide a very good source of nectar. There are several species of small beetles that feed on the foliage. They are also food for the Brown Argus and Green Hairstreak Butterfly caterpillars and the Wood Tiger Month caterpillar.
Helianthemum nummularium together to other species of Helianthemum have been grown in cottage gardens for medicinal purposes for over many hundreds of years. They contain labdanum, which can be used to treat ailments such as bronchitis and dysentery. In addition, they can be used in perfumes and as an incense fumigant.