This plant is usually described as being half hardy. Is it worth
trying to get it through the winter by keeping a cloche over it until
spring, or must I make sure of rooting some cuttings before it is too
late?

I am unsure as to whether a cloche provides protection only for the
top growth, or for the roots as well.
Who has experience of overwintering nearly hardy plants with the aid
of a cloche?

Franz