What about astilibe, some of them get up to 48" tall. Also bellflowers and columbines. I have an area on the side of our home that is the same as yours, I have successfully grown believe it or not, mums, iris, and lady's mantle, as well as hostas and forget-me-nots. My mums are huge and they must get enough sun to perform well there. You could also think about hydrangeas, they like morning sun and would probably do well there. Hope this helps.

Where to begin. These all are hardy perennials, easy to grow in decent soil.

Thalictrum - Meadow rue, 3+' espcially 'Elin' 5+'
Cimicifuga - bugbane (aka actea)3 - 4'
Kirengeshoma - waxbells (sp?) 3 - 4'
Aruncus dioicus - goatsbeard 3'
Anemone tomentosa 'Robustissima' Grapeleaved Anemone 3'
Aconitum - monkshood - 3' + or -
Saruma 30"

Hydrangeas and astibles are good sugestions as well. Boxwood might be a nice solid evergreen shrub or even a rhododendron.

Have fun!

Ted

Ligularia is great needs water
Azalias
Rhodadendron
Jewel weed -pink is taller, there beautiful but reseed massivly
Valarian-white