I grew lots of different hardy geraniums "two houses ago" (having moved 3 times in five years didn't give me a chance to do much with the other garden) and am starting on the garden here at my new place. My favorite is G. pratense var. striatum which is often sold as "Splish Splash". Not sure whether it comes true from seed or not. The flower is described either as blue with white flecks or white with blue flecks and stripes (take your choice! :-). Like all the pratense's, it can get tall and rangy looking if not cut back somewhat after flowering. It's a good plant for a mixed border with other plants of some decent height, such as the taller campanulas. Geranium cantabrigiense is a super all-purpose border and edging plant. The different varieties such as Biokova (or Biokovo), St. Ola, etc., all go well with each other. There is also a white form, or there used to be. It is larger overall than New Hampshire purple. Geranium 'Ann Folkard' is great if you like intense dark magenta flowers with a black eye, and a lot more compact than G. psilostemon with gets to be about three times the size. That said, there's nothing quite like a few G. psilostemon plants in the border to stop traffic (I saw some once that were almost 4 feet tall and threatening to smother the lilies!). I also like the varieties such as G. macrorrhizum and maculatum which have very nice reddish fall color. Not all of the hardy geraniums do. 'Ann Folkard', for instance, just goes yellower. If you really want to get into hardy geraniums, there are two REALLY good books: 'Hardy Geraniums' by Peter Yeo (Timber Press, 1985) and 'The Gardener's Guide to Growing Hardy Geraniums' by Trevor Bath and Joy Jones (David & Charles Publishing, 1994). You can also join The Geraniaceae Group which is based in Dover, Kent, England. They publish a quarterly newsletter and have an annual seedlist. Originally they were part of the British Geranium and Pelargonium Society Group (divison of the RHS) but separated off during the mid or late 1980s and became a separate entity. There is, in fact, a link to some more info here on Gardenweb. Here is a link that might be useful: Geraniaceae Group information

When I lived in Nebraska, we'd plant ours in the ground in springtime and dig them up in the fall and keep them in the house, and repeat each year. They'd look awful in the spring when we'd first plant them...they would lose their leaves and look bad for a month or so, but then, they'd put out new growth and look amazing all the rest of the spring/summer. They'd get around 3 feet wide and almost as tall...the most amazing geraniums you've ever seen! We found out it's a good idea to cut it back after planting in them outside in the springtime. Then you can stick the cuttings in the ground and the'll root almost 100% of the time...giving you more and more each year.

It is Geranium robertianum, aka Herb Robert, a wild annual species that is considered a noxious weed in many parts of the country. Although quite hardy, often growing and blooming throughout winter in my climate, I wouldn't go to the effort of overwintering it. It self sows prolifically. As Trevor Bath notes: "It often appears in the garden uninvited, looking delightful in the chink of a shady wall or paving. Turn your back and it will soon cover the whole garden, bedding itself comfortably in your most treasured small plants - you have been warned!"

I'm not sure which geranium you are referring to as cranesbill is a common name sometime used for any geranium. Some need sun to bloom, some are not so drought tolerant. I think the best one for dry shade is geranium macrorrhizum (there are several varietys -- all good). This is a vigorous geranium and very tolerant of almost any conditions.