I'd recommend G. sanguineum or cinereum. They'll both tolerate full sun and heat but require evenly moist soil.

There are literally dozens of species of hardy geraniums and many more hybrids and named cultivars. And they all offer various attributes, including being able to grow in just about any gardening situation one could imagine. However, you need to do some research to determine what would work best for your particular circumstances. There's some great geranium reference books out there (check your library or book stores) and a few websites that are very helpful as well.

Here is a link that might be useful: this one's not bad

G. wallichianum and its offspring such as 'Rozanne' and 'Jolly Bee' are usually pretty good in hot sun, at least up here.

gardengal, are you sure about G. cinereum liking heat? I would think it would suffer, e.g. "in the south".

Carla, where are you from?

Mistake in my post: I wasn't thinking that the area where they will go is only half day sun. My Johnson's Blue does great and I wanted another variety but, maybe I should do the whole border of this bed in Johnson's Blue. I could even split some of my JB.
Has anyone grown a Splish Splash that impressed them?
I live in Western NC below the mtns.

Thank you,
Carla

CPG, it's native to the Pyrenees, which get darn hot in summer :-) However, that is an alpine environment so the humidity that accompanies summer heat in much of the more southern areas of this continent (and even parts of the east coast and midwest) may not be much to its liking. It definitely prefers full, open sun in my climate.

Hi Carla, it depends what height and width of plant you want in that area. Most will do well in part sun if the soil is at least average moisture. Jolly Bee or Rozanne bloom a long time. I would classify them as medium height. The sanguineums are shorter, wider plants and take more dryness (very tough plants). The cinereums are more compact than the sanguineums, but also relatively low-growing. 'Nimbus' is very reliable for me in mostly sun and fairly dry soil. There are many, many from which to choose. Check out some Geranium web-sites and you will start drooling.