All you need to know about growing Delphinium in your garden
Elegant spires of blue, lavender, mauve, pink, purple, red, or white, up to 8 feet tall, develop above lobed or fanlike leaves. All are perennial (though most are short lived). Provide full sun and regular water.
Varieties of candle delphinium (D. elatum; zones A1-A3, 1-10, 14-24) are the most dramatic of the genus. For the tallest blooms, try mixed colors of the Pacific strain or named varieties ('Blue Bird', 'Galahad', 'Summer Skies').
Large-flowered Centurion grows 4 to 5 feet tall and will bloom the first year from seed when planted in spring. It's also more reliably perennial. Blue Springs and Magic Fountains mixes are shorter (to 2 1/2 feet tall).
Varieties of D. x belladonna (zones 1-9, 14-24) are shorter (3 to 4 feet tall) and have airier flowers. The plants are also longer lived than the tall varieties of D. elatum.