How about Hostas, lots of varieties and colours, also Heuchera and Tiarellas again, good colours. Spring, plant some white bedding along the front of it, this always give a good bright pop of colour. Busy Lizzies and Begonias come to mind. Oh, also ferns, lots of lovely selection and textures. Talking of planters, see my next post
Good Luck, Mrs Bouquet