The new film from writer-director Peter (Dan in Real Life) Hedges is 104 minutes long and doesn’t contain a single believable moment. I hated this movie. Lots of pictures are contrived, mindlessly sentimental and cynically manipulative, but few are also as infuriatingly stupid as this one.

Wow. I’m not even sure where to begin, there’s so much to despise and ridicule here. I suppose the beginning is as bad as any place.

Jennifer Garner and Joel Edgerton play Cindy and Jim Green, an idealized small-town couple who’ve spent years trying to conceive. The day their doctor informs them that further fertility treatments are pointless, the two go home and do what any heartbroken couple would do. They write the qualities that would describe their dream child (“Honest to a fault,” “He rocks”) on scraps of paper, place them in a handsome wooden box they just happen to have lying around and — what else? — bury it in the backyard.

Cue the magical lightning storm. Awakened by strange sounds in the middle of the night, Cindy and Jim open the door to the room they’ve reserved for a baby, only to be confronted by a courteous 10-year-old (Cameron Adams) who’s covered with mud and calls them “Mom” and “Dad.” I don’t have to tell you there’s a hole in the ground where the box used to be.

Though I should mention that, in addition to being otherworldly and wise, the boy has leaves sprouting from his ankles and shins. A nice, high pair of socks keeps this little secret under wraps when the pair’s entire extended family coincidentally shows up on their doorstep first thing the next morning for an elaborate reunion.

This being a modern Disney fairy tale, nobody bats an eye when Cindy and Jim introduce the unannounced addition to their household. Everybody’s too busy being tedious, single-trait characters to make much of the sudden appearance of an elfin preteen who periodically stops, raises his arms and faces the sun in a kind of salute. The instantly tiresome clan includes David Morse as Big Jim, Jim’s emotionally distant dad; and Rosemarie DeWitt in the thankless role of Cindy’s smugly competitive sister, Brenda.

These relationships amount to little more than window dressing and filler, however, since the focus is on the bond between Timothy and his green-thumbed parents. The script provides — “forces” may be a better word — one opportunity after another for him to display the attributes they assigned to him that fateful night. A low point is the scene in which “he rocks.” You know the makers of a movie have run out of ideas when they resort to the obligatory everybody-dances-to-a-peppy-pop-song sequence. This may be the most cringe inducing ever.

Did I mention the story takes place in the fall? Timothy’s fate is revealed early on, so no spoiler alert is necessary when I remind you what happens to leaves with autumn’s arrival. That’s right. Be sure to bring the Kleenex. Are we having fun yet?

The Odd Life of Timothy Green is a shameless, clueless heap of hokum and the low point in the career of everyone involved — with the possible exception of Ahmet Zappa, who’s credited with having come up with the story. The third child of the late, great Frank Zappa, Ahmet has been a game-show host and all-around Hollywood bottom feeder for years. This may actually be a step up for him. The old man must be spinning.