Trivia

The title sequence, by graphics designer Douglas Burd, was shot on 35mm film and used quantized color levels in stark relief against a black background. Burd was killed during production when his self-made plane crashed during a flight.

Each 8-foot-tall triffid prop concealed an operator on a go-kart seat in a fan-cooled, 5-foot diameter base. The base was modelled on a ginseng root. Two of the props were later used in a carnivorous plant display at the Natural History Museum in London, England.

Mortar bombs are ineffective against Triffids because they share a tree's ability to take great damage without lethal harm. Or they can wait for their prey to emerge just by putting down roots to lull people into a false sense of security and then suddenly spring to life and attack, even a passing car, covering the windscreen in their poison. Spraying the ground with arsenic can deter Triffids but only temporarily. If they do find a way in they'll surround a house right up to the windows. Wearing protection from the Triffids includes thick clothing, gloves, a leather helmet, goggles and a mesh mask. You could hack your way through with a carving knife wearing all this, but their poison can penetrate a mask if there are enough of them. Triffids can collapse a fence (even if reinforced) by concentrating their efforts, even if it means dying in the attempt. Triffids can be electrified but not without a steady power source.

The book ends with the Triffids still a threat and Masen leaving for the Isle of Wight, hoping to eradicate them from the face of the Earth someday.

Elisabeth Sladen, who had worked for producer David Maloney when he was a director on Doctor Who, was offered a role.