Hi, I would like to plant some colourful, hardy, aphid-resistant perennials in two concrete planters. The planters have a southern exposure, but are partly shaded by some tall maples growing by the street. One planter has a dwarf willow already growing in it, and the other has a weeping birch, which seems to attract aphids. I would like plants that grow between 20 and 100cm tall. Does anybody have any suggestions? I was thinking of lupines, but I'm not sure if they will enjoy the light. Thanks, in advance.