A sinister landscaper turns into a tree and learns to communicate with his fellow plants.

Carl the Gardner (Joe Dallesandro), grows odd plants for a rich Yankee woman Ellen Bennett (Katharine Houghton) living in South America while exercising a mental hold over her. All his previous employers died mysteriously. Some of his plants emit deadly fumes. Houghton previously starred with her aunt Katharine Hepburn in "Guess Who's Coming to Dinner."—alfiehitchie