Grade: D-

If the words “directed by Garry Marshall” aren’t enough to scare you off “Georgia Rule,” surely the addition of “and starring Lindsay Lohan” should do the trick. Marshall hasn’t made a movie that even approached tolerability in years, and Lohan’s track record isn’t much better. But together they outdo their individual faux pas with a seriocomic take on a dysfunctional family that’s a berserk combination of tasteless comedy and even more tasteless melodrama.

The initial premise has something in common with “Secondhand Lions,” though Mark Andrus’ script is much less genial. Well-to-do San Francisco mom Lilly (Felicity Huffman) brings her rebellious teen daughter Rachel (Lohan) to stay the summer with her estranged mother Georgia (Jane Fonda) in a small Idaho town. All three are troubled characters. Rachel is nasty-tongued, demanding and inconsiderate, and acts the part of a young seductress. Lilly is harried and, we learn, an alcoholic. And Georgia is outwardly brusque and rigid, though she has a soft side for the two kids she hosts—Sam (Dylan McLaughlin) and Ethan (Zachary Gordon)—while their parents are at work.

Lilly quickly decamps, leaving Georgia and Lilly, who’ve barely met before, to bond as best they can. Georgia doesn’t help matters by forcing the girl to work as a receptionist to kindly Doc Simon (Dermot Mulroney), a veterinarian who also tends to human folk, and who just happens to be the fellow Rachel forced to give her a ride into town when her mom dumped her on the road—as well as, we later learn, a one-time boyfriend of Lilly’s. And Rachel shows her troubled side by coming on not only to Simon, but to hunky field hand Harlan (Garrett Hedlund), a sweet-tempered Mormon who finds the loose girl’s attractions irresistible—something that makes him feel unfaithful to his intended, a petite thing off at a nearby college.

But all that becomes secondary to Rachel’s big revelation to Georgia—that she’d been molested by her stepfather Arnold (Cary Elwes), a wealthy lawyer, a fact that perhaps explains her promiscuity and generally bad attitude and brings a distraught Lilly back into the picture, desperate to determine whether her daughter or her husband is lying. It isn’t long before she’s back on the sauce in a big way, and Georgia has to become a real mother again as well as a new grandma.

The narrative elements here are bad enough individually, but collectively their awfulness increases exponentially. On the one hand Marshall tries to make “Georgia Rule” a sometimes comedy, though some of the gags (like having tyke Sam attracted to Rachel in a most revealing way) are really distasteful. But at other points it’s an over-the-top soap opera, especially in the plot threads involving Lilly. And then, of course, the whole molestation theme takes us into the realm of grim cautionary tale and (since Rachel recants her accusation) mean-spirited “he-said-she-said” melodrama. As if that weren’t enough, the picture’s references to Mormonism reek of caricature, not just in terms of Harlan and his insipid girlfriend, but her friends, who take it upon themselves to keep a close watch on him after his confession in some of the movie’s most deplorably farcical moments.

The cast is helpless in such circumstances. The haggard-looking Fonda and the skanky-acting Lohan are both unbearably shrill, though in different ways, and Huffman plays most of her scenes as though she were in a state of shock, which may have resulted from reading the script. Mulroney and Hedlund coast on good-natured niceness, but casting directors should certainly learn one major lesson from the picture: if you’re looking for somebody who can convincingly play a guy who may or may not be a sleazeball, Cary Elwes is not your man. Ambiguity is beyond his range. Of course, nobody would fare well under Marshall’s sledgehammer direction, which pounds home every obvious point while letting the rest of the movie limp along lackadaisically, including the scenes involving his usual good-luck charm, Hector Elizondo, playing a Basque (!) with a hernia. (Well, at least he has a reason to look pained.) On the technical side, the movie barely passes muster, even with cinematography by the skilled Karl Walter Lindenlaub. The editing by Bruce Green and Tara Timpone is especially inept; great chunks of the story seem to have been mislaid along the way. (Not that one would want them restored.) And John Debney’s score is as obvious as Marshall’s direction.

It took a kind of crazy courage to mix such disparate elements in a single movie. But in the event it proves to have been a foolhardy choice.