I've used perennial geraniums in the past but grew wary of their self-seeding. Some of them literally moved around a garden from year to year. Rozanne (actually it seems 'Gerwat') is a sterile interspecific hybrid (also Plant Breeders Rights Protected). The previous likely best blue, 'Johnson's Blue' is also an interspecific hybrid, as is 'A.T. Johnson', etc., above and I'm guessing they're also sterile. It's very clear from GW that there's lots of perennial gardening styles within the same hardiness zone. Personally, I don't want perennials to pick their own location within a garden (unless perhaps to tell me where they'll grow best). The fact that Rozanne definitely stays put is another plus for such an excellent Geranium cultivar.

I have some Gallardia but not sure of the color and burgendy peony poppy if your interested.

The botanical name is Dietes bicolor , common name Yellow Wild Iris. Dietes previously belonged to the Moraea group but was seperated as it has a rhizome rather than a corm like Moraea. The plant naturally occurs near streams and marshy places in the Bathurst district of the Eastern Cape. Though occuring near wet places it is drought hardy (and frost hardy). It grows best in full sun with lots of water and well composted soil though light shade is also ok. I have found that it needs a lots of water to flower well. Afrikaans people refer to it as as a Rainlily because it often flowers just after good rains. Another name is the Peacock Flower. You can divide the clumps if it gets too crowded after a few years but it is not really necessary and has a detrimental effect on the plant. It does not need to be cut down each year either. I have found that trimming the plant every so often of all dead or discoloured or straggly leaves and the heavy seed/fruits keeps it looking neat. You should try to find someone with the white wild iris (Dietes grandiflora) and do a trade. The white one has larger flowers , flowers more and is very pretty with its white flower with purple and yellow markings. Garrick

I have grown this outside in Cheshire for more than 10 years and never seen any damage. It flowers each year and then occasionally I have to get in and hack out the dying (it is monocarpic) heads. I have some offsets rooting at the moment but they can take up to 2 years outside to root. It is tough as old boots. Best regards Chris