Posted: 22/02/2016 at 21:25
Tootles, usually I am a "curves" guy but they would look odd and contrived there.
You can create an illusion of curves with your selection of plants....a bold planting of 3 or more of, say veronicas, can look more imposing than, say a single low grass or sedge and emphasize the difference. Even more dramatically a tall miscanthus grass and/or verbena Bonariensis will interrupt the eye when a low planting precedes it.
Mixing groups with single specimens, mixing textures like phormiums and libertias with mounds like heucheras and santolinas etc.can create
one or two evergreen shrubs like pittosporum, holly or whatever can add to the variety too. .
And that wall....cover parts but expose parts too. A jasmine for scent would be good for example.