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Cistus - Growing Guide
Cistus Overview
Rock or sun roses consist of 19 species from Mediterranean countries and, particularly, Spain and Portugal. They have hybridised in the wild and many new forms have been bred in cultivation since gardeners first became interested in these plants in the 1860s.
Cistus are quick growing and widely popular plants present, in some form, in most British gardens. They are also widely grown in municipal settings. They are frost hardy in a normal winter but clearly suffered widely in the 2018 ‘Beast’ as they did in the extremes of the 1962/3 winter. The hardiest forms in extremes of weather are said to be C. ‘Silver Pink’ and C. x corbariensis. Before worrying unduly about threats of cold it should be understood that these are short lived plants which flower and seed profusely. In the main they respond badly to pruning (except perhaps when young) and after only five to eight years you may find them becoming old and straggly and in need of replacement. In the nursery the plants overwinter badly in 2 or 3L pots (unless potted on in late summer) and quickly outgrow the energy available in the compost by the start of the second season. Without care they already look elderly and unsaleable.
Cistus thrive in poor or moderately fertile soil and need a well-drained site in baking sun for best results. They are perfectly lime tolerant but may go yellow and chlorotic in very chalky soils. While you cannot prune cistus you can pinch back the new growth after flowering to make the plants more bushy.
Rock roses are some of the easiest softwood cuttings you will ever attempt in summer. Seeds can be sown in containers as soon as ripe but, if you and your neighbours grow more than one variety of cistus, then you are unlikely to get anything but a mixture of forms.
Cistus are some of the bestselling plants in our catalogue but they should be ordered in March or April and planted straight away to get a good show in the first summer.
Characteristics
These comprise a genus of 15 to 20 species of evergreen shrubs. They grow in the wild in the Mediterranean region and, particularly, Spain and Portugal as well as North Africa, Turkey and the Canary Islands.
The flowers normally have five petals and usually last no more than a day. Flowering is concentrated in June and July when a constant succession of flowers appear in sunny weather.
Cistus hybridise freely both in the wild and in gardens so plants bearing the same name (eg Cistus x skanbergii, Cistus x aguilari) can be quite variable in reality.
These are relatively short lived plants and need to be removed and replaced when they have scruffy dieback often in the centre of the plant.
Many cistus exude a fragrant gum from their young stems and leaves. C. creticus’ foliage has been used in perfume making.
Hardiness
Rock roses are, unfortunately, not genuinely hardy although there are some exceptions. They will readily survive our normally mild winters with some frost but can easily be killed in severe ones especially where subjected and exposed to cold north or east winds. Such losses are however easily replaced and some which do succumb will be elderly plants anyway. C. x corbariensis, C. x argenteus ‘Silver Pink’ and, perhaps, C. ladanifer are generally hardier than other species and hybrids.
Positioning
Cistus like a light, well drained soil and, more than anything, a position exposed to full sun. Perfect on a sunny bank or against a wall or in containers. Ideal for hot coastal locations as well.
That is not to say that they should not be carefully sheltered from cold winds in winter.
They are generally lime tolerant but will probably become chlorotic on very chalky soils.
Cistus never suffer from drought but a fleece cover over the plants will help them survive extreme weather. Bracken can also be used for this purpose.
Pruning
It is not necessary to prune rock roses at all. You may however choose to do so to improve and encourage a bushy habit. Pinch back the sappy new growth after flowering to achieve this.
Cistus, particularly when mature, dislike being pruned back hard to the older wood and can often respond by dying. Older, leggy plants are best replaced rather than pruned as they will seldom respond with new growth.
Propagation
This can readily be achieved by seed or cuttings. Not all forms of cistus actually set any seed and cuttings of this plant are easily rooted. The cuttings are best taken in late summer and rooted in mild heat.
Seeds should be collected and sown in a cold frame as soon as they are ripe in the autumn. They can also readily be stored over winter and sown in the spring. If you grow several varieties of cistus in your garden (or have neighbours who do) do not expect the seedlings to all come true!
We have a more detailed article on collecting, storing and planting seeds if you wish to know more.
Cistus that grow well in Cornwall
The cistus which grow best for us in Cornwall:
sticky leaves and solitary white flowers with a dark red mark at the base of each petal.
very hardy in coastal locations, low growing and forming a mounded bush with endless pink flowers.
Plants
