Delphinium is a genus of about 250 species of annual, biennial or perennial flowering plants in the buttercup family Ranunculaceae, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. The leaves are deeply lobed with 3-7 toothed, pointed lobes. The main flowering stem is erect, and varies greatly in size between the species, from 10 cm in some alpine species, up to 2 m tall in the larger meadowland species; it is topped by many flowers, varying between purple, blue, red, yellow or white. The flower has five petals which grow together together to form a hollow flower with a spur at the end, which gives the plant its name. The seeds are small and shiny black. The plants flower from late spring to late summer, and are pollinated by butterflies and bumble bees. The scientific name is taken from Dioscorides and describes the shape of the bud, which is thought to look like a (rather fat) dolphin.
These popular perennials prefer full sun with well-drained soils that are slightly alkaline. Plants are heavy feeders, requiring fertilizer twice over the growing season. Some varieties may need to be staked.
Dwarf Delphinium grandiflorum "Blue Mirror" grows under 1 ft tall. Very different from the traditional tall spiky Delphiniums, this selection forms a low, bushy mound. Plants bear loose sprays of single electric-blue flowers the entire summer long. Ideal for containers, the rock garden or edging in the sunny border. Tolerant of hot, humid summer climates.