Agapanthus, geraniums, canna, verbena, argyranthemums, begonias, dahlias, marigolds, fuchsias, salvias, and fruit trees like olives and lemons are among the many plants that can't be planted ...
Grasses are also repeat flowered, as are salvias and a burgundy-leafed Lunaria. A red-leafed cultivar of Knotweed also adds glorious foliage colour, offset by grey-green globe artichokes.