Retaining walls are a fact of suburban life. Use plants to soften the hard edges of a long run of masonry.
A wall planting puts flowers at eye level. And some, like bleeding heart, helleborus, and spiderwort, have pendulous blossoms that are best appreciated when viewed from below. Of course, the area along the top of a wall can be hard to get to. And in this case, it receives unrelenting late afternoon sun. So it called for plants that thrive on limited care: sedums, catmint, poppy mallow, santolina, Montauk daisy, lavender, pink fairy roses, purple campanula, evergreen juniper, and willowleaf cotoneaster, which has small green leaves and brilliant red berries that persist all winter long.