Caryopteris is a low-maintenance, small deciduous shrub with colourful blooms in late summer and autumn. There are several cultivars, with flower colours ranging from white and baby pink through to all shades of blue. The mounds of downy aromatic leaves range from mid-green to silver to variegated, with silvery undersides. The small flowers cluster in whorls along the stems and have a fluffy appearance, thanks to their long anthers. Thriving in full sun and tolerant of drought, this is an attractive shrub for a cottage, gravel or wildlife garden.
How to grow caryopteris
Grow caryopteris in well-drained soil in full sun to partial shade (you’ll get more flowers in sun). Prune hard in spring to encourage strong new growth that will bear flowers later that year.
Where to grow caryopteris
Grow caryopteris in well-drained soil in full sun in a herbaceous or mixed border. Depending on the variety, it grows between 50cm and 1.2 m high, and the same distance across, so position it either in the middle or at the edge of the border. If your soil is wet or waterlogged, grow caryopteris in a pot, again siting it in full sun and perhaps near a walkway or seating area so that as you brush past you can enjoy the scent of its aromatic leaves. Extend the flowering season by teaming it with Mediterranean summer-flowering plants such as lavender and cistus, or combine it with other late-flowering perennials like salvia, aster, rudbeckia and crocosmia.
How to plant caryopteris
Caryopteris is deciduous, so ideally plant it in spring, when the soil is warming up and it’s just starting into growth. Water well while it’s still in its pot. Dig a hole slightly bigger than the rootball and plant it to the same depth as it was in its pot, back filling and firming the soil around it. Water thoroughly to settle the soil around the plant and water regularly for a few weeks after planting. If planting later in the season, you may need to water occasionally if leaves begin to droop in prolonged dry spells.
Caryopteris is hardy, particularly if it is planted in well-drained soil, but in regions with very harsh winters, where temperatures drop to below -15’C, it should be planted in the shelter of a wall and will need protection if it is grown in a container.
How to care for caryopteris
Caryopteris needs very little care. Once established, it doesn’t need watering or feeding, unless in a container, in which case it should be watered in spring and summer when the top 5cm of compost is dry. Caryopteris is not evergreen and will drop its leaves in late autumn. Leave them where they fall and they will be drawn underground by soil organisms, such as beetles, millipedes and earthworms, where they’ll improve the soil.
How to prune caryopteris
Prune caryopteris in spring. As it flowers on the current year’s stems, cut back hard in spring to encourage new growth. Wait for the first signs of leaves emerging, and then cut back to pairs of strong buds on the woody frame. Cutting back all old stems to the same height will produce a balanced, mounding shrub with lots of flowers.
How to propagate caryopteris
Propagate caryopteris by greenwood or softwood cuttings in summer. Take 15cm cuttings from new growth that is not yet woody. Remove all but the top-most leaves, insert into a pot of cuttings compost, cover with a plastic bag or transparent pot and place in a bright spot out of direct sunlight. New leaves will indicate that the cuttings have rooted and can be transferred to individual pots until big enough to plant out. The new plants will be exactly the same as the parent plant.
Caryopteris can also be grown from seed, harvested late autumn when the seed heads are brown and dry. Sow the small nutlets immediately on the surface of damp seed compost, leave outside in a cold frame for the winter and they should germinate in spring. If you live in a region with very mild winters, ‘stratify’ your seeds by mixing them with a little sand in a closed container and putting them in the refrigerator for six weeks. This mimics winter conditions, through which the seeds stay dormant. Once the seeds are removed from the cold and sown, the change of temperature stimulates germination. The seedlings that result may differ from the parent plant in flower colour and foliage.
Pests and diseases
Caryopteris are not affected by pests and diseases, unless they are grown in waterlogged soil.
Advice on buying caryopteris
- Most caryopteris for sale in the UK are cultivars of Caryopteris x clandonensis, although this may not be specified and they may just be labelled as Caryopteris plus their cultivar name. They are sometimes called bluebeard, although this is primarily in the United States. They are grown and sold in pots
- Seed is not available commercially, so ask a friend who has it in their garden to harvest and share it if you’d like to try growing from seed
- Always check plants for signs of damage or disease before buying or planting
Where to buy caryopteris
Caryopteris varieties to grow
Caryopteris x clandonensis ‘Heavenly Blue’ – azure flowers, grey green foliage. Height x Spread: 1m x 1m
Caryopteris x clandonensis ‘Dark Knight’ – dark blue-purple flowers, grey green foliage. H x S: 1.2m x 1.2m
Caryopteris x clandonensis ‘Hint of Gold’ – deep blue flowers, yellow green leaves. H x S: 90cm x 90 cm