Plant Man From Space is the 6th produced episode and the 4th broadcast episode of the series Fireball XL5.
A missile from space lands at Space City. It doesn't explode, but instead a strange, quick-growing plant covers the place.
Hormones from the planet Hedera will destroy it, but when the crew of XL5, along with Dr. Howard Rootes, who has just arrived after experimenting with plants in space, land on the planet they are met by a 'Plant man' the creation of Rootes, who has become obsessed with plant life. Robert the Robot must come to the rescue.