Experts and BHG readers answer.
Are you suppose to split delphiniums after they have finished blooming and what other care is required for them?
Generally, you don't need to divide delphiniums. Delphiniums like cool summers. In warmer areas, they're short-lived and die out before they need dividing. Many gardeners are unaware that delphiniums can produce a second flush of blooms. Right after the flowers fade, remove the flower stalk down to the top set of leaves. If your plant is situated in a spot where it's happy, it should send up another flower stalk. It probably won't be as large as the first, but you will still get two sets of blooms for the price of one!