Easy to grow, compact shrubs, up to 1m (3â…“ft)
Rich blue flowers from late summer to early autumn
Aromatic leaves, usually grey-green
Easy to grow in sun and well-drained soil
Drought tolerant and dislike damp conditions
Deciduous, so they lose their leaves in winter
Cut back hard in spring to encourage flowering
Flowers are attractive to pollinating insects
Caryopteris are easy-to-grow, drought-tolerant shrubs, prized for their lavender-blue flowers. These are held in fluffy clusters along the stems from late summer into autumn, and are followed by small inflated seed capsules. The flowers are a magnet for bees and butterflies in late summer. The leaves are usually small, grey-green and aromatic.
Most caryopteris available in the UK are hardy cultivars of Caryopteris x clandonesis, or occasionally C. incana. They are , so lose their leaves in winter, and need full sun and light soil that drains well after rain.
Caryopteris are easy to grow in the right conditions, so before buying, make sure you can offer them a warm, sunny spot in light, free-draining soil or in a large container.
These compact shrubs work well in most sizes and styles of garden, especially in mixed borders, cottage-style plantings, dry gardens, gravel gardens, pollinator-friendly borders, and containers.
They mingle harmoniously with pastel shades – perhaps alongside repeat-flowering roses, cistus or lavenders. Also, as blue flowers are unusual in late summer, you can make a bonus of this by contrasting caryopteris with fiery-hued late perennials, such as orange crocosmias, golden rudbeckias or red-leaved hylotelephium (formerly sedum).
The most widely available caryopteris are hardy cultivars of C. x clandonesis, although you may come across a few cultivars of other species, such as C. incana ‘Blue Cascade’. They all like similar growing conditions and are broadly similar in appearance, but there are some variations to bear in mind when choosing and positioning them:
Flower colour
Plant shape
These shrubs generally grow to a maximum of 1m (3â…“ft) tall and wide, with some variations in plant shape and size, including:
Leaf colour
Most caryopteris have grey-green leaves, but a few offer alternatives that may require specific growing conditions:
To browse photos and descriptions of caryopteris cultivars, go to RHS Find a Plant. Several have an RHS Award of Garden Merit, which shows they performed well in RHS trials, so are reliable choices. Many also have our Plants for Pollinators award, as they provide a valuable late source of for bees, butterflies and other insects.
Caryopteris are widely available in garden centres and nurseries, and from online suppliers. They’re usually sold in pots of 2 litres and larger, throughout the year, although the selection is likely to be at its fullest when plants are in flower in summer.
To track down a specific , go to RHS Find a Plant.
Spring is the ideal time for planting shrubs with silver and greyish foliage, as the worst of the winter cold and damp is over and the is ahead of them.
Still, containerised caryopteris can be planted at any time of year, although it is best to avoid extremes or hot or cold weather, as they may struggle to get established.
Caryopteris are widely available right through summer and early autumn, and are often bought in flower for instant impact. If you plant in summer, be prepared to water regularly, especially in hot dry spells, until the roots are well established in their new home.
Caryopteris are very straightforward to plant. Just follow the RHS guide below to shrub planting and container planting.
Additional tips for planting in containers:
Caryopteris don’t need feeding and are happy in moderately fertile and even poor soils. Too much fertility can lead to excessive leafy growth at the expense of flowers.
Apply a thick mulch of organic matter, such as home-made garden compost, to the soil around caryopteris in spring, to deter weeds and improve the soil structure and drainage. Take care to leave a gap around the base of the stem, so it isn’t in contact with damp , which could encourage rotting.
There's no need to deadhead caryopteris, as the flowers open in succession up the stems, so cutting them off would curtail the ongoing display. Plants also go on to produce small inflated seed capsules, initially dark or greeny-blue, ripening papery brown, that continue the interest into winter.
Caryopteris are generally hardy in the UK, down to at least -5°C or lower, although they may suffer some dieback from harsh, late frosts. This is not usually a problem, as light damage can be cut out during annual pruning in spring.
However, in colder regions or gardens prone to severe frosts, take care to plant in your warmest, most sheltered spot, in very free-draining soil – perhaps at the base of a sunny wall. Or grow in a container that can be moved indoors to avoid the harshest weather.
Caryopteris should be pruned every spring to keep them compact and flowering strongly. They can also be pruned lightly after flowering.
New plants can be grown from seeds collected from the papery seed capsules in late autumn. The resulting plants may differ slightly from the parent plant, although this may give you interesting results.
Caryopteris are generally trouble-free plants, suffering few pests or diseases when given the right growing conditions. But do look out for:
More advice
If you’re a member of the RHS, you can use our online Gardening Advice Service, via MyRHS, for any gardening problems or queries.
