I am seeking advice on mass planting for a long south-facing (but shaded by trees) brick retaining wall. The wall is about five feet high and over a hundred feet long. I'm presently thinking of a mass of just one or two types of cascading plant--something with a good 'structural' texture, and that stays green in winter. I favour white and blue flowers. (please see attached image) I have seen some impressive cascading arabis and aubretia-- but do they grow long enough to hang down four feet? I am also wondering if the wall will be sunny enough to promote good growth, as-- though south-facing-- it is shaded by a long line of trees. In gardens in England I have seen lithodora growing against walls to excellent effect, but again I wonder how well it will do in partial shade --or would you call that "filtered sunlight"? I'm interested in the Greenstreets program in the City of Vancouver, and would be pleased to hear from any gardeners who are involved in boulevard gardening.
