Clematis 'Kaiser'

Clematis 'Kaiser' was raised in Japan in 1997 by F. Miyata and K. Miyazaki as a sport of 'Allegro' and introduced in 2009. It was originally meant to be called 'Emperor', but the Japanese authorities rejected the name — so it was given the German translation 'Kaiser' instead. Its 10-14 cm double flowers consist of eight large violet-pink outer sepals and up to 200 narrow, upright inner petals that open yellow-green and gradually turn pink.

With a compact height of 100 to 150 cm, 'Kaiser' flowers from May to June and ranks among the early large-flowered cultivars. Its neat, bushy habit makes it an excellent choice for pots, obelisks and low supports on balconies and patios, as well as for smaller gardens where abundant blooms are wanted in a small space. 'Kaiser' has already been awarded medals at international exhibitions for its full, double flowers.

'Kaiser' is exceptionally winter-hardy (zone 4, down to about -34 °C) and copes well with harsh winters without extra protection. As a Group 2 clematis, it only needs light pruning: cut the stems back to about 100 cm in June, keeping the plant compact and ensuring a generous flowering the following year.