Cultivation is in southeastern England, and in the Mediterranean area, especially in southern France. The opening of the florets on a spike lasts for over a month.
Opening occurs primarily in the morning.
The stamens and style of a flower are enclosed in the bilabiate corolla. Nectar is produced in the corolla at the base of the ovary. At flower opening, the anthers unfold exposing pollen on their upper surfaces. The stigma, however, remains in the immature stage, not even reaching to the middle of the corolla tube, so that insects removing pollen cannot pollinate it. The stigmatic lobes then diverge and are receptive to pollen, but the pollen from the same flower has already been removed by insects.