Selected in New Zealand, the New Millennium Delphinium strains outperform all other tall types and offer some astonishingly rich shades. 'Double Innocence' produces tall, stately spires with frilly double flowers of creamy white. The deeply-cut leaves form a medium-sized bushy mound with superior vigour. Stems may require staking in windy areas, best done before they reach 3 feet or so in height.
Delphiniums generally thrive in cooler climates so avoid planting where it is extremely hot and sun baked. They grow best in rich, well-drained soil with a basic pH. If your soil is naturally acidic, adding lime will help to provide these conditions. They are also heavy feeders. The addition of compost or manure to the soil will result in healthier, stronger plants.
Delphiniums can be grown in full sun or partial shade. Good air circulation may help to prevent powdery mildew. When planting, be sure to set the crown at or above soil level to avoid rot. Since their stems are hollow, taller varieties of Delphiniums should be staked to prevent damage from wind and rain. These new hybrids tend to be longer lived than their short-lived cousins but may be propagated from basal cuttings.