Big blank wall! Your little row of flowers is all out of scale and nearly invisible next to it. I would put a full size tree (that will get as tall as the bottom of the eaves) next to it, properly spaced away from the house, with a couple shrubs and and some flowers, stepping down in height as you go away from the house. You have plenty of room to make a beautiful bed there. A tree in front of that afternoon sun wall will keep it cooler, help keep the house fron heating up.
Things I always suggest in landscaping: be big and bold, make it in scale with the big house behind it. Make your bed in curves, the house is a big box, it can be softened with curved beds. Plant things in groups, not in straight lines, there is no such thing as a straight line in nature.
Here's a few landscaping threads I have done in the past with inspiration pictures:
http://www.helpfulgardener.com/forum/vi ... 12&t=57400
http://www.helpfulgardener.com/forum/vi ... 12&t=56975
http://www.helpfulgardener.com/forum/vi ... 12&t=53331
http://www.helpfulgardener.com/forum/vi ... =8&t=52070
some of these are about front yards, but all the same principles apply.
Applestar's idea of edibility could be incorporated in there with a dwarf fruit tree or serviceberry as the anchor of the bed and berry bushes for shrubbery. I always try to use native plants, since they will be much hardier and more low maintenance being adapted to your area and because they provide food and habitat for the local birds, butterflies, etc. which imported trees usually do not.
If you like these ideas, come back and I will make some suggestions for trees, shrubs, etc that might work in your conditions.