My neighbor who lives across the street of me planted white standard iceberg roses with a hedge of french lavenders in the front yard. It matches perfectly with the white picket fences. They use blue stone /bricks to hedge the garden bed.

It creates this really nice comforty, cottage feeling. My neighbor sticks to the white, green, blue, and silver color scheme. Almost a white garden....They grew this climbing SOLANUM JASMINOIDES - that produces floriferous white flowers throughout the season, along the front porch.

Points to consider: What color is this retaining wall? and would you intend to plant other flowers beside these roses and lavenders? I'm pretty sure that bright red and yellow colours would destroy this cottage feeling if blended together with those lavenders and white roses.

I've always see my neighbor pruning their roses and lavenders deeply...so if you're after a low maintenence planting scheme - I don't think it's a right choice. The roses would loose their leaves in winter etc. In my honest opinion - that kind of planting look nice in the front yard along the white picket fence - prove me wrong.

Have you consider a row of camilleas? Or maybe a hedge of dawf size apple trees....or maybe a hedge of star jasmine?