Clematis 'Eriostemon'

Clematis 'Eriostemon' is one of the earliest crosses between Clematis integrifolia and Clematis viticella, making it a close relative of 'Hendersonii', raised in Great Britain in 1835 — experts at the International Clematis Society see only minor differences between the historic selections from this cross. Its nodding, bell-shaped flowers are 5–7 cm across, glow in rich blue-violet, and are beautifully set off by creamy to yellowish stamens.

From June to August, 'Eriostemon' puts on its floral display, growing up to 300 cm tall. Like its close relatives, it is not a conventional climber but a semi-shrubby clematis that threads loosely through shrubs, roses and perennials or leans against trellises and obelisks. It thrives in both full sun and semi-shade and suits south-, west- and east-facing positions — ideal for naturalistic perennial borders with enough room to spread.

'Eriostemon' is very winter-hardy (Zone 5, down to about -28.8 °C) and reliable even in harsh locations. Cut the plant back to about 25 cm in March so it sprouts vigorously and densely in spring — this corresponds to Pruning Group 3, as also given by the Royal Horticultural Society for this cross. Like many historic clematis, it needs a little time after planting to establish before showing its full flowering potential.