Actors turned directors fall roughly into two types. Some are committed to directing as a craft, e.g. Ida Lupino, Clint Eastwood, Robert Redford, etc. For others, craftsmanship takes second place to personal expression. Their films aren't as slick as the other group's but are unmistakably personal. That lineage goes back to Charlie Chaplin, and Mel Gibson is probably the exemplary figure in that category today. Cornel Wilde belongs to that lineage, and in his attention to violence and suffering Wilde, who directed eight films over twenty years, looks like a direct precursor to Gibson. No Blade of Grass in some ways looks like a precursor or prequel to Mad Max, the George Miller film that made Gibson a star. Wilde's clumsy flashforwards, his self-indulgent solarization, and his heavyhanded pictorial editorializing sometimes make Grass look like the missing link between Mad Max and Jean-Luc Godard's Weekend in its apocalyptic pretentiousness. David Thomson says of Wilde's films that they sometimes make you believe they're the first movies ever made, and Grass, adapted by Wilde under a pseudonym in collaboration with Sean Forestal from a John Christopher novel, approaches its subject as if no one had considered such stuff before. In fact, Wilde was not the first actor to visualize the collapse of civilization; Ray Milland beat him to the punch with Panic in Year Zero! several years earlier. Maybe actors have some special appreciation of how fragile the veneer of civility actually is, but that's a topic for another time.
In Grass the environment is buckling under human pressures, from population growth to pollution -- Wilde can't show enough pollution -- and some people are starving while others enjoy plenty. In case this isn't crystal clear to you, Wilde cuts back and forth from TV footage of starving Africans to Brits stuffing their faces at a well-stocked buffet. Soon no one will enjoy plenty, as a grass-killing plague spreads around the world. John Custance (Nigel Davenport, starring in Wilde's on-screen absence) and his brother David (Patrick Holt) get the straight dope from their government friend Roger (John Hamill). David heads north to start a potato crop that will ensure a food supply for his extended family, and invites John to bring his family to safety. By the time John's family (his wife is played by Jean Wallace, the current Mrs. Wilde) gets going things are already falling apart. Their trek grows progressively more dangerous as civilization deteriorates rapidly into violent predatory factions, and the Custance party has to leave their scruples behind to survive.
The Custances pick up allies along the way, though some are of dubious value. Pirrie (Anthony May) proves the most dangerous, killing his own woman in a fit of jealousy and eventually claiming John's daughter for himself while demanding equal partnership in their journey. The tense relationship of Pirrie and Custance holds your interest until the small band starts growing, most people recognizing strength in numbers, though our protagonists have to kill the leader of a larger band to get them to go their way. Ironically, as everything else falls apart this motley group (including a token "Paki") pulls closer together, effectively defending themselves against a gang of horned-helmeted, tactically challenged bikers in the picture's action highlight. The more bitter irony emerges when John's party reaches David's farm, only to learn that David, understandably not anticipating such a large group, refuses to allow anyone in but John, his immediate family, and Roger. In what might be seen as a last stand for civilization over tribal kinship, and at the same time as an ultimate breakdown of human order, John decides to lead his band in a hostile takeover of David's compound, putting the group before family.
The first half hour or so of Grass is pretty bad, but once Wilde gets outdoors he's on familiar turf. His recognized masterpiece is The Naked Prey, a film that consisted of himself being chased by African tribesman, and Grass proves again that he has an eye for landscape and people moving through it with dramatic urgency. As John Custance's band grows the film builds real momentum, despite everything Wilde does to sabotage himself with pointless flashforwards previewing events to come a few minutes later.There's a real sense of tragedy in the final confrontation between the brothers that survives Wilde's portentous narration and the dreadful folk song that opens and closes the film. There's no getting around the fact that No Blade of Grass is a profoundly awkward move -- never more awkward than in a montage crosscutting between a young mother's doomed labor and John's flashback to his wife's first childbirth, highlighted by out-of-nowhere graphic birth-of-a-baby footage of the sort that used to be shown to adults only with a lecture and booklets for sale. But if you tried to smooth all the rough patches in Wilde's work you'd probably lose most of the knobby authenticity and rugged power they have. You have to take the bad to get the good, and fortunately there is some good in Wilde to justify the effort.