Vinca is one of the few plants that seem happy to hang and doesn't try and climb back up itself, Jenny Pym is a named form of Vinca difformis

Vinca Jenny Pym004 by charliepridham, on Flickr
Its fair to say its never going to set the world on fire! But its one of those work-a-day plants you can rely on

Vinca Jenny Pym by charliepridham, on Flickr
As the weather warms the flowers darken

vinca jenny pym2 by charliepridham, on Flickr
Elsewhere in the garden I have lived to regret planting Vinca major and minor as ground cover as it can, after years of looking OK suddenly get out of control, but Jenny can stay until I think of something better :)