Vioalcea Plena is a magnificent variety of Japanese wisteria. This climber bears 30-40 cm long racemes of double, deep violet, scented flowers that make this plant a fantastic show-stopper when in full bloom. In English-speaking countries it is often sold under another name: Black Dragon (and Yea Koku Riu in Japan).

It is a late flowering cultivar that flowers along with leaves which is May to early June. It may take 3-5 years to start flowering. Being late in flowering it escapes late frosts. Exotic-looking deciduous leaves are mid green, pinnate and large. It likes acid, reasonably fertile soil that is moist but well-drained. No fertilizing recommended. Abundant flowering can be achieved by regular pruning – cut back longest shoots several times a year. It needs full sun, very young plants can be damaged by harsh winters. Fully hardy to about -29°C (USDA zone 5).