Centranthus ruber 'Coccineus' (Red Valerian) - h18-30" x w18-24" - Full Sun, Part Shade - Very fragrant crimson red flowers. A not-so-common perennial that should be used more often for its continual display of flowers and unfussy growth habit. The leaves are opposite on stems which offer a different texture than most perennials. Zone 4. Benefits: Fragrant.