Delphinium ‘Guardian Blue’ Delphinium elatum 'Guardian Blue' Type:perennials that last Notable Traits:attracts butterflies/pollinators, great cut flowers, heirloom garden plant Hardiness:Zone 4 – 7 Mature Height:4-6ft Bloom Color:blue, purple Bloom Shape:spike Foliage:green Description Tall spires of bright blue flowers atop strong stems are excellent for cutting and emerge from the mounding clumps of deeply lobed foliage. A superb specimen for the back of the perennial border.