Delphiniums thrive in regions with relatively cool and moist summers, and often struggle in hot, dry summer weather. However, some new varieties are more tolerant of heat. Flower color includes blue, red, white, and yellow; however, the rich, clear blues are especially prized by many gardeners. The plants bloom in late spring to early summer, and the flowers are suitable for cutting.
Select a site with full sun to light shade and well-drained soil. Choose an area protected from strong winds to keep tall, top-heavy varieties from blowing over. Apply a thin layer of compost each spring, followed by a 2-inch layer of mulch to retain moisture and control weeds. Stake tall varieties to prevent hollow flower stalks from snapping in the wind, and deadhead after flowering to encourage re-blooming.