I have this dream of having a huge bed of all different kinds of delphinium. I was told that they will become the same color over time. Do I have to segregate my delphinium?
In ''the industry'' delphinium refers to the perennial, Delphinium elatum. This plant should remain the same color for it's life span. If delphinium are pollinated, and the seed germinate, growing to bloom, eventually, yes, you will have plants of the same color. If you cut the spent bloom spikes off before seed ripen and/or fall, your plant will not change color. Larkspur, Delphinium ajacis, is a biennial, meaning that you sow seed year one. The plants bloom year two, are pollinated, form and drop seed. That plant dies, the seed germinate and bloom year three. You generally let the seed drop for the next years flowers. Unless those plants are segregated, you will end up with the same color. (Hope this didn't confuse you too much.)