Posted: 16/08/2015 at 10:55
I agree with Nut too. Keep the grass formal or lose it all together and go for deep planting with lots of shape and form and texture.
If you do want more colour, there's a lot of bare wall that could be covered with more baskets, troughs and pots. Depends on how much time you have for watering and dead heading and general tending. If you can make a decent planting hole, you could also think about planting a climbing rose to cover the walls.
Whichever you do, Dove's suggestion of big pots in the corners is worth considering.