Posted: 11/04/2017 at 19:58
Mint needs its roots to be dampish, so you may need to water it in the summer, but otherwise it should be fine. It'll die down in the winter - in early spring chop whatever remains down to ground level and it'll shoot up again.
Every three or four years dig it all out of the bed, keep the youngest pieces of root and replant and throw the rest away.
Lovely part of the world ... I spent a lovely summer in the Dinard, Quimper, Nantes area with my children a long time ago.