Caryopteris × clandonensis 'FERNDOWN' bluebeard, blue spirea
Symbivit Tric (arbuscular)
Symbivit (arbuscular)Caryopteris
The genus Caryopteris belongs to the mint family and includes only a handful of species native to the mountainous and dry regions of eastern Asia, from China across Mongolia to Japan. In the wild they grow on rocky slopes, river terraces and steppe margins, where hot summers alternate with cold but mostly dry winters. The first botanical descriptions appeared in the 19th century, when European herbaria began to fill with plants brought back from expeditions to then little‑explored parts of Asia. The genus was described with a degree of uncertainty, as the species were similar to one another and herbarium collections often contained transitional forms. This ambiguity later allowed the formation of a hybrid complex that became the foundation of modern garden bluebeards. Although botanically modest, the genus gained a reputation in horticulture as a reliable late‑season source of nectar and colour at a time when most shrubs have long finished flowering.
Caryopteris × clandonensis originated from a chance cross between two Asian species, C. incana and C. mongholica, in the garden of Arthur Simmonds (1877–1937) in Clandon, England, in the 1930s. Simmonds was an amateur grower with an exceptional eye for plants, and he noticed that the seedlings in his garden shared a uniform appearance and unusually long flowering. The hybrid quickly spread among growers because it combined the drought tolerance and resilience of one parent with the finer texture and richer flowering of the other. In temperate climates it became valued not only for its late colour but also for its ability to attract bees and butterflies at a time when other nectar sources are fading. Over time it gave rise to a whole group of cultivars that today form a distinct chapter of the garden assortment, alongside shrubs with similar requirements such as buddlejas, perovskias or hypericums.
Ferndown is a bluebeard variety offering a little bit more compact habit as opposed to the species. In late summer it has profusion of deep violet blue flowers that attract bumble bees and butterflies. The narrowly lance-shaped leaves are somewhat blue-green with silvery undertone. They have an interesting scent which recalls cooking herbs. From pollinated flowers Ferndown bluebeard manages to makes seeds in mid autumn, they are green and blue so the colour play continues even after the flowers have gone.
The shrub grows fast and has to be pruned hard every spring to about one third of previous year’s growth to encourage strong, new branching that will bloom even more profusely. It forms an airy bush yet keeping a nice fountain-like habit. It is a very nice addition to late summer and autumn borders combining well with pink gauras and feathery grasses.
Last update 18-10-2015
Bluebeards need full sun and light, well‑drained soil that warms up quickly in spring. In heavy clay they suffer from winter wetness, so in compacted ground it is better to plant them slightly raised so the roots never sit in water. Watering is needed only during establishment; later they tolerate drought better than waterlogging. Feeding should be modest, ideally a small amount of compost or slow‑release fertiliser in spring. Pruning is done early in the season, removing old wood and shortening the previous year’s growth to about 20 percent of its length to encourage strong new shoots with flowers. They are unreliable in containers because they need excellent drainage yet are sensitive to drying out in pots. Wind is not a problem. Hardiness is around –25 °C, but the main risk is winter moisture rather than cold itself (USDA zone 6)
