Delphiniums are spectacular with tall spikes of flowers in shades of blue, purple, lavender, and white. They are a classic in the back of the mixed perennial border and make an excellent cut flower. They bloom abundantly in late spring to early summer. If plants are cut back and given a feeding after the first bloom, a second, lighter bloom can be enjoyed in the early fall. Delphiniums prefer a rich, well-drained soil high in organic matter that is slightly alkaline or at least neutral. Good air circulation is essential to prevent mildew so space about 2 feet apart. Staking is recommended for the tall types. Cultivate gently, as they are not deep rooted. In optimum conditions delphiniums are fairly long lived and should be divided about every third year. This is best done in the early spring before there is substantial new growth.
There are many varieties of delphinium. Pacific Giants come in a wide range of colors and can attain heights of 5 feet.