Preferences:

A European perennial that stands tall and must be staked

It prefers full sun in a moist well drained soil. Likes slightly alkaline organic soil with high fertility.

Cultural Practices:

Propagation - Sowing in small pots to avoid root disturbance is best, barely cover the seeds at 10 - 18 degrees for up to 30 days.

Culture - Delphiniums are high maintenance plants. They must be staked in unprotected conditions or near fences because of the wind. In spring when they are about 6" up treat with a systemic like Lagon as a soil drench. This will treat Delphinium leaf tyre when left alone will eat the flower buds. Often after they have finished flowering many members of the Ranunculaceae are suspcetible to powdery mildew. You can treat by adding 1 tablespoon per gallon of baking soda to water to upset the pH and hinder the mildew.

Landscape Value:

Common Cultivars - The Pacific Giants series is the most popular (4' - 6'). Of these I like 'Black Knight', and 'King Arthur'. Absolutely must be staked and the extra tall stalks need to be further wired

Magic Fountain Series - 3' - 4' Tall with a mix of colours. 'Blue Fountain' is beautiful.

Other Plants - Delphinium grandiflorum - 'Blue Elf' and 'Blue Mirror' are two dwarf varieties. This type of Delphinium does not have flowers on a tall single stem but have flowers in a bush like form. The intensity of the blue is very head spinning.

Delphinium consolida - Larkspur - is an annual form of delphinium, excellent  look but the spikes are thinner looking than the Giants.