Lisa D’Amour’s surreal backyard fable, Detroit, escalates into a frenzied Bacchanalia.

Before I can talk about Lisa D’Amour’s blazing comedy-drama Detroit, I should say a few words about lawns.

In drought-plagued Southern California, a healthy lawn’s an eyesore, a waste of precious water. In the Midwest it’s the opposite. Your lawn — and the bigger, the better — says who and where you are. A bounding span of weedless green, kept trim by one of John Deere’s vehicles — the bigger, the better — and you’re on the fast-track of the middle class. You handle economic duties, provide for family, etc., and have time to manicure a mini football field.

A few years back, a friend moved to Cleveland, Ohio, and rented a house with a lengthy lawn. When a neighbor introduced herself, she spooked and begged my friend not to be like the former residents. “They just let their lawn run wild!”

The playwright chose Detroit for her title because the name evokes “a particular anxiety”: Detroit “is a symbol...of the American Dream drying up.” But the first stage direction says the locale is “not necessarily Detroit.” Could be Cleveland, Madison, whatever. And she says Ben and Mary were raised “somewhere inland, Kansas City, maybe Denver.” The nonchalance is curious. No big whup. Whatever.

But this, in a way, is how Ben and Mary have lived. They have trod the proscribed path: college, marriage, no beer-drinking in the front yard. Whenever a doubt nagged, they dismissed it with “whatever.” Numbing alcohol and internet addiction kept doubts at bay. But when Kenny and Sharon move in next door — wild-eyed, tatooed, and carefully treading up the 12 steps — Ben and Mary’s “whatevers” come home to roost.

Kenny and Sharon met in rehab. Or was it before? Whatever. They rode “that glossy motorcade of substances” and now combat it in different ways, says Sharon: “He’s all, ‘I’m trying to be proactive,’ and I’m all, ‘Today sucked.’” Though starting from scratch, both have jobs; unlike Ben, recently laid off, and Mary, soon to be. After five weeks, Mary notices no changes to Kenny and Sharon’s weedy yard: “Not even a single FERN. You’ve made no effort.”

The playwright is quite specific about one thing: the adjoining homes are in a once-thriving “first-ring” suburb, which is now a no-person’s land between foreclosure and “starter house” gentrification — a space, in effect, of uncertainty.

Dionysus was the god of the grape, among other things. At a backyard party, the suburban quartet evokes the god of Bud Light. The “beer-wasted” par-tay metamorphoses into a ritual out of Greek drama. It’s a “truth fall,” says Sharon, “a healing ritual.” It looks more like mania, but when Ben and Mary fall, their free-spirited, off-the-wagon neighbors are there to catch them.

The playwright said Detroit feels like a “surreal fable.” Though quite good in many ways, San Diego Rep’s production doesn’t always sustain that balance. Director Sam Woodhouse has tweaked some scenes for comic effects. But the humor often glosses over the rabid desperation, as when Sharon craves her crack pipe and gets a laugh — or when Kenny admits to a lack of hope, and it comes as a surprise.

D. Martyn Bookwalter’s set solves a major problem: how to put two very different backyards on the same stage? Simple: use a turntable and Jekyll becomes Hyde. Detroit has a running visual theme: things and people are accident-prone, as if the world itself were breaking down. The set functions quite well here: at once sturdy and fragile and, in the end, flammable.

Bookwalter’s lighting, however, overstates contrasts. And it implies a judgment when he bombards Kenny and Sharon’s backyard with a red aura so obviously satanic it looks cartoony.

Though at times oversized, the performances always impress. Lisel Gorrell-Getz unpeels Mary’s defenses with arias of angst. Summer Spiro makes antsy Sharon a dervish on speed. Jeffrey Jones’s Kenny taps into the play’s darker reaches to good effect. And Steve Gunderson shines as Ben, a nerdy phoenix whose true self emerges from the ashes of the old.

Detroit was a finalist for the 2011 Pulitzer Prize. The playwright takes a no-holds-barred look at economic hardship. She also makes a choice that feels a bit odd: most of the exposition comes in the final scene and wraps the play in a veneer of forced nostalgia. On the plus side, the legendary Robert Benedetti (dean of Cal Arts; chairman of Yale’s acting program) makes the revelations matter.

The denouement follows the Rep’s best scene. What starts as a backyard party, with everyone wanting to “unfurrow,” escalates into an impromptu ritual of leaping and dancing. Then it escalates again. And again into a frenzied Bacchanalia that banishes all inhibitions. The quartet, so to speak, just let their lawns run wild.

Detroit, by Lisa D’Amour

Directed by Sam Woodhouse; cast: Lisel Gorell-Getz, Summer Spiro, Jeffrey Jones, Steve Gunderson, Robert Benedetti; scenic and lighting designs, D. Martyn Bookwalter; costumes, Jeannie Galioto; sound design and composer, Kevin Anthenil; projections, Victoria Petrovich; choreographer, Brian Bose

Playing through March 16; Sunday, Tuesday, and Wednesday at 7:00 p.m. Thursday through Saturday at 8:00 p.m. Matinee Saturday and Sunday at 2:00 p.m. 619-544-1000. sdrep.org