Clematis 'William Kennett'

Clematis 'William Kennett' is one of the oldest large-flowered cultivars, raised in England around 1875 from a cross between Clematis lanuginosa and Clematis patens. The raiser is usually given as G. Jackman & Son. Its flowers are 14–16 cm across and violet-blue, with a delicate rose-pink shading and crimped margins. The six to eight overlapping sepals carry a light red bar at the base, and purple to dark red stamens on white filaments sit in the centre. In sunlight the middle of the flower fades slightly, giving the blooms an attractive two-tone look.

At around 300 cm, 'William Kennett' climbs vigorously up trellises, obelisks and climbing frames. The first flush appears in June, with a second flush continuing from July into August. It thrives in sunny to partly shaded spots and enjoys moist, well-drained soil.

'William Kennett' is reliably hardy (zone 6, down to about -23 °C). For strong growth and a rich second flush, cut the plant back to about 100 cm in June. Like other early large-flowered hybrids it is prone to clematis wilt, so keep the stems healthy and undamaged.