Macrorrhizum's are clump forming hardy geraniums that are an excellent goundcover for shade. They bloom in my zone (6) in late spring, early summer. The flower on Ingwersen's is pink. Because macrorrhizums tolerate dry shade, I grow them under my maple. Rozanne, my favorite, needs more sun. In your zone, part sun may be fine. She has a blue flower. Rozanne is sterile. She grows into a clump that flops into a large clump. She starts to bloom in late spring and never stops until October. Last year she bloomed into November for me. Johnson's Blue has a similar flower to Rozanne and similar light requirements but does not bloom as long.

While not blue, a stronger-colored "Big-root" Geranium (macrorrhizum) would be 'Bevan's Variety'. Don't discount them.

And, one of my favorites, G. cantabrigiense (Biokovo) 'Karmina'.

While the varieties and cultivars of geraniums are many, they are quite different as to size and habit, bloom color, leaf shape and color and other attributes such as leaf fragrance, fall color and winter presence. They are some of my favorite perennials.

In addition, the macrorrhizums are highly deer resistant--mine have never, ever been eaten. Pretty much all other geraniums--Rozanne included-- are deer candy.

I only the Cranesbill hardy geranium. Are they a long lived perennial?

Yes, though I don't grow all varieties. I do have several varieties, most probably have been here for 20 years, all continue to thrive through deer, drought, and changing sun/shade conditions.