Oh, Sue, I love your Carmella. I have only seen that grafted at Edmunds. I also love your Lady Hamilton. Purple and coral/orange are a favorite garden color combo for me too.
I grow Carefree Celebration (a cousin of the knockouts which I also saw at Home Depot today if any one is looking for that one - a coral colored rose by Radler, the knockout breeder, which has been hardy for me for several years in zone 6a) with Johnson's blue geranium. I posted pics of those before in my old garden. They survived and will be growing together again.
