The title was inspired by a scientific study into the male erection which divided the erection into a hardness scale consisting of tofu, peeled banana, banana, and cucumber.
The company HC Clements, which appears in the first episode of "Cucumber", is also a subsidiary business affiliated with Russell T. Davies' version of Doctor Who (2005). It is the company Donna Noble works for when she first meets the Tenth Doctor in The Runaway Bride (2006).