Solanum rantonnetii syn Lycianthes rantonnetii

Solanum rantonnetii showing colour variation in flower from dark purple to blueSolanum rantonnetii, blue potato bush or 'Royal Robe'

This rambling thin stemmed shrub from Argentina and Paraguay is nearly always in flower and only has a brief rest during the coldest part of winter.It is certainly versatile and can be grown as a shrub to about 2 metres in sun or semi-shade ,trained as a climber flat against a wall or even shaped into a standard.There is a golden variegated leaf form as well which is sometimes available.

It is hardy down to about minus 3C.
2017 update: I currently don't have any stock of it.