perennials buddleia davidii `nanho blue nanho blue butterfly bush size 7 ... exposure sun foliage green flower blue buddleia davidii `nanho purple nanho ... green flower violet buddleia `petite indigo petite indigo butterfly bush size 5 ... exposure sun foliage green flower lilac blue buddleia `petite plum petite plum ... bush size 5 8 exposure sun foliage blue-green flower purple calmintha nepeta nepeta ... 18 exposure sun foliage green flower blue calamintha nepeta `white cloud white ... 18 exposure sun foliage green flower blue caltha palustris marsh marigold size 12 ... flower yellow campanula carpatica `blue clips blue bellflower size 6 9 ... sun to 1/2 shade foliage green flower blue campanula carpatica pearl deep blue ... pearl deep blue bellflower size 6 9 exposure sun to 1/ ...