The garden is large and open and in the height of summer, my only means of escape from the midday sun is seeking some shelter under the branches of a large tree or a purpose built pergola where I can take a rest every now and then. I find, as I get older that I have less tolerance to the sun every year; it is a good job that it is not the same for some plants. Fortunately, for them, their tolerance of the midday sun is far greater than mine, and one of my favourite sun loving plants is the Helianthemum and I am about to show you why.
Helianthemums; also known as Rock Roses are just perfect for any sunny site that needs a splash of colour. The name Helianthemum comes from the Greek word Helios meaning sun and Anthemum meaning flower, this name gives us a clue as to the conditions that these perennials like. Part of the Cistaceae family, a small group of plants (about 25 genus) recognised as shrubs profusely covered in flowers at time of bloom, that prefer dry and sunny habitats and grow well on poor soils. Relatives of the Cistus and Halimiocistus, there are over 150 different varieties now of Helianthemum originating from North America, Europe, West Asia and North Africa, but mainly centred in the Mediterranean area.
Helianthemums are a semi-evergreen low spreading shrub about 15-30 cm (6-12”) high. Originally, they were yellow saucer shaped flowers with orange stamens held above green foliage with a grey underside but over may years they have been cultivated and now have flowers ranging from white through yellow to deep red and they are now available in double and semi-double flowers as well. What we have today are tough, hardy, drought tolerant and trouble free. They produce glorious colour from late spring right through to midsummer and with a little pruning after flowering, they will reward you with another flush of flowers for late summer. They make excellent groundcover and are perfect for filling gaps in rockeries, gravel gardens and sunny, dry borders. They are nectar rich and the flowers really stand out against the silver-green foliage attracting bees, butterflies and other pollinators.
They are so easy to care for, the abundance of flowers it produces do not last very long and if you just pinch off the faded flowers and others will replace them. They will grow best in a moderately fertile soil in full sun. A Neutral or Alkaline Loam, Chalk, Clay or Sand soil type is best. Helianthemums dislike wet ground, so heavy soil can be improved by adding coarse grit or sharp sand before planting. Once established they become drought tolerant, but young plants will need feeding and watering through the growing season.
It is obvious that the many varieties of Helianthemum will complement each other when grown in clusters; here are some of the varieties that we grow at the nursery