Alpine Garden Society

Ulster Group

Plant of the Month, August 2007
Clematis x Cartmanii Joe - Sam & Jean McEwen
This plant has an interesting history. Its parents are Clematis marmoraria (from the ‘marble mountains’ in New Zealand), and C. paniculata (the NZ native puawhananga). It arose in 1983 from a batch of seed sent by Joe Cartmann of Christchurch to Henry and Margaret Taylor, and was named Clematis x cartmanii 'Joe' by them. Native New Zealand clematis are dioecious being either male or female. 'Joe' is a male, thus never sets seed and must be propagated vegetatively.
Jean & I have been growing this particular plant in this container (earthenware) for at least 10 years. At first we did not prune it and grew it over a wire frame, but now we set it on a step and allow it to tumble down.  It remains outdoors over the winter and flowers profusely in March & April.  We now prune lightly after flowering and feed it to encourage new growth from the base - these branches then flower the following year.  It prefers a sunny position in the shelter of the conservatory.