Delphinium (Delphinium Cultorum Summer Skies) - For these lovely, impressive perennials, grow Delphinium seeds! Delphinium Summer Skies is marked by immense, graceful, light to medium blue flower spikes with white 'bees'. If Delphinium flower seeds are sown in early spring, Delphinium Summer Skies will bloom the first year putting on a mid-summer show of color. Summer Skies is from the Delphinium Pacific Giants series and it can reach a height of 6 feet. These tall beauties create a wonderful back border for the perennial flower garden, or plant them in a mass in the center of an island garden. Delphinium grow best in full sun; however, in hotter zones they may be planted in bright shade areas that still receive some direct sunlight during the day. They thrive in rich, deeply worked soil that drains well. Prefers cool, moist summer nights. Space plants approximately 30 inches apart for optimum performance. Grows well in zones 3 - 7, but in hotter zones you may need to treat as hardy annual. Delphinium Cultorum care includes applying a balanced liquid fertilizer every month as Delphinium plants are heavy feeders Season: Perennial USDA Zones: 3 - 8 Height: 70 inches Bloom Season: Summer Bloom Color: Light blue Environment: Full sun