Strangely, this is a volunteer seedling from 'Blue Ensign', who rarely seeds. We watched the seedling in its original location for two years and both years it was decidedly more compact, growing in a nice round bun-shape. We watched them another year side by side, in large pots, with same result. Additionally it's bluer overall, with fewer flowers truning purple/pinkish. Easy, low maintenance perennial for the border and shade garden.