Delphiniums offer color to gardens through much of the summer with a relatively long blooming season. A hardy perennial, the delphinium can reach 8 feet in height and spread horizontally to about 2 feet. The flower blooms in pink, white, blue and purple. Proper handling techniques can extend the blooming season beyond its normal range.
Delphiniums bloom in the first weeks of summer, depending on local weather conditions. Some hybrid varieties bloom a few weeks later in midsummer. Flowers can be cut for indoor use and will typically last about one week before wilting. If the flower is left on the plant, it may require a stake to hold the rather weak stalk steady during winds.
Clipping the Blooms
Cut the flower stalks after the bloom begins to dry. This practice is particularly important with the Chinese delphinium, which will continue to bloom through the summer if the drying blooms are clipped after each flower completes its cycle.
The delphinium will bloom again in the fall if the flower stalks were clipped during the summer bloom period. Commonly the blooms are not as large as the summer blooms.
While the delphinium is a perennial, it typically lives three years or less in standard garden conditions. The flower will behave like an annual and bloom the same year it is planted if the spring planting is done early enough and conditions cooperate. Some gardeners treat the plant like an annual and replant every season rather than planning on the plant coming back year after year.