Huge clusters (up to 4” across) of sky blue flowers with a dark blue-purple edge are held on dark stout stems that need no support above beautiful emerald foliage from June to September. Great for cutting. Attractive to butterflies. Will spread to form wide clumps so great for summer ground cover. Prefers moist but well-drained soil in sun or part shade. Height & spread 50cm (20”). Hardy perennial.