Ever notice how well the Studio Theatre does with wooden porches, worn kitchens and the trampled-down yards lying just beyond? Two of its most accomplished productions -- "The Member of the Wedding" and "The Fifth of July" -- unfolded in just such unpretentious surroundings and the Studio animated them with the kind of easy naturalism that also recognized the poetry in weather-beaten slats and screen doors.

To that list, we can now add "A Walk Out of Water," Donald Driver's drama about a gawky young girl coming of age on an Oregon farm, and the blind grandmother who eases her through the perils of adolescence. Granted, Driver is not in the same league with a Carson McCullers or a Lanford Wilson, although he certainly seems to be following in their footsteps with this work, which opened a four-week run on Sunday. But much of the evening is heartfelt and appealingly eccentric. If you do not go looking for bolts of lightning -- merely fireflies -- it is very likely to win you over.

You should probably not look for an ending, either. Driver is giving us a slice of life -- inspired, in part, by his own family history. Like most slices of life, it moseys along, finding its truth in daily rituals, passing squabbles and the antics of children who don't always remember to do what they're told. At the end, however, Driver feels compelled to whip up a luridly melodramatic conclusion that will catch you up short. If it registers as a defiantly wrong note, it's because so many of the notes he has sounded before are right on key.

Indeed, his female characters are drawn with a loving appreciation of their idiosyncrasies, their strengths and their stubborn determination to resist the reckless male ego. Blindness has pretty much relegated Gramma Rinn (Katherine Squire) to a lumpy armchair on the porch, where she listens to music on her tape deck, taps out the rhythms with her feet and sips at her daily ration of whiskey. Her body may be frail, but her mind is as lively as a bumblebee in a zinnia patch and she's acquired the wisdom of the very old, which is to say a sweet acceptance of the folly that infects the rest of the human race. Ignorance, she announces, is not only bliss; it's how you avoid the world's aggravations.

To the extent that it has a plot, "A Walk Out of Water" details Gramma Rinn's attempts to hold on to a patch of land on the hillside. Her loutish son-in-law (Beau James) wants her to sell it so he can purchase a second rig for his failing trucking business. But she intends to postpone the sale until her two grandchildren are ready for the college education she never had. When her furious son-in-law points out that the land is just "sitting there," Gramma Rinn replies with cheerful obstinacy, "That's what land does!"

Although this tug-of-war provides the underlying tension and fuels that last-minute explosion, it's the least persuasive aspect of a play that flowers mainly when the pressure is off. The best moments of "A Walk Out of Water" are those Gramma spends with her grandchildren -- 13-year-old Jennie Mae (Erika Bogren), who nurtures romantic dreams of being a writer and views life as a fancy-dress ball; and 7-year-old Little Lyle, who is probably mentally retarded and possibly an arsonist. (Gramma prefers to describe him as "kissed by an angel.")

Oblivious to any difference in their ages, they pass the time in idle chatter and reenact the "historic moments" that have captured Jennie Mae's imagination. Quite the loveliest -- and silliest -- interlude has the three of them re-creating the sinking of the Titanic on the back porch with a shotgun, a ukelele and the spangled leftovers from an attic trunk. But Gramma's no fool, even if she's willing to look like one. All the while, she's instilling a firm sense of morality in her grandchildren, encouraging them to resist the stultifying ways of adulthood.

At 81, Squire's vibrancy and humor are only slightly less than miraculous, and her twinkling spirits get the script over more than a few hurdles. Bogren, playing a 1980s version of Frankie Addams, continues to develop confidence as an actress -- you can see the bloom of young womanhood in her now -- and the Studio has found an adorable tot, Chad Wain, who portrays strange Little Lyle with an utter lack of self-consciousness.

When "A Walk Out of Water" ventures beyond their charmed circle, it loses some of its magic. Still, Lynnie Raybuck, as the put-upon mother who has come to see herself as "an old farm dog," has a certain bedrock gallantry in the face of adversity and a mate who swats her around. The play's biggest deficiencies reside with that husband. Driver tries to motivate the meanness in his soul, but the character is barely a peg above the drunken villain of melodrama and James' performance offers no further refinements.

If the surly husband seems patently out of place, I suspect it's because Driver, who has also directed this production, hasn't fully come to terms with the disturbing implications of his play as a whole. By emphasizing Gramma's indomitable ways, he has created a crowd-pleasing character. But he's also robbed "A Walk Out of Water" of its deeper drama: Jennie Mae's difficult rites of passage. The canvas really is darker, more surrealistic, than Driver or the Studio is acknowledging right now.

Set designer Russell Metheny understands. His meticulously detailed creation of a roadside farmhouse, complete with an automobile tire for a swing, is a perfect piece of Americana. Then night falls and the porch is no longer the safe, sunlit haven it once was. What makes it threatening, however, is not the blackness from above, but the gathering gloom within.

A Walk Out of Water. By Donald Driver. Directed by Driver. Set, Russell Metheny; costumes, Ric Thomas Rice; lighting, Stuart Duke; original music, Michael Valenti. With Katherine Squire, Lynnie Raybuck, Erika Bogren, Chad Wain and Beau James. At the Studio Theatre through Dec. 22.