Our driveway in front of the house doesn't get any sun what so ever, but we want to soften up the driveway tarmac area with some pots and maybe some window boxes. Are there many flowers of trailers that are suitable for full shade, and also are OK in window boxes? I know shrubs seem to tollerate shade better, but we really don't have soil there to house shrubbery, only pots and window boxes. It needs softening up really. I have done a bt of research on the web about this, but alot of the plants suitable for this are not available at regular garden centres.