Not all delphiniums are blue! Originating from Siberia, this rare species produces yellow flowering spikes in the late summer following sowing. It is a short-lived perennial and looks great in a vase indoors as well as at the back of the border, so make sure you grow enough for cutting. The flowers were once used to dye silk. Sow Feb- May; flowers May-Jul. Height 76cm (2 1/2 feet).