An apple got Adam and Eve thrown out of paradise. In Linda Joan Smith’s glowing debut novel, a peach shows a 13-year-old girl the way in.

It’s 1850 in Lancashire, England. The orphaned Scilla Brown is hungry and alone after the death of Dora, a lowlife who took her from the Ormskirk Workhouse to be her accomplice in petty crime. The memory of one bite of stolen peach haunts Scilla: “Oh, that bite. What dreams were made of.” She sneaks into the local earl’s garden one evening in search of more, crashing to earth when the espaliered cherry tree she has scampered up to make her getaway breaks free from the wall.

Enter Mr. Layton, the head gardener, with a beastly scar on his face and “a voice of rusty nails, sharp with anger.” He collars Scilla, mistaking her for a boy because of her trousers and short hair. To her shock, rather than hauling her off to the magistrate he puts her to work scrubbing plant pots. Bolton Hall, the earl’s estate, requires many hands to maintain. Soon Scilla has a new life as Seth Brown, garden boy.

“Brownie” gets plenty of food, a warm place to sleep, and the joshing fellowship of the bothy, the lodge where the garden staff gathers. She works hard, eager to stay as long as she can. Self-worth begins to sprout through the hard soil of experience.

Mr. Layton lends her gardening books, teaches her how to care for seedlings, and demonstrates how to pack delicate grapes and pears away for the winter. “Plants need limits,” he tells her. “As do people.” Nobody has seen value in her before, and she can’t quite believe it. The head gardener looks fearsome, but “behind his hardened scar” he’s “wick, full of life, like the stone of the peach itself.”

So is Mrs. Nandi, his Indian housekeeper, who carries her own scars and sees through “Brownie” before anyone else does. (Mrs. Nandi’s presence, along with the cultivation of exotics in the earl’s garden, hints at the colonialism that built estates like Bolton Hall.)

Every garden is a secret garden, revealing wonders, if you know how to look. Smith, an author of garden books and the former editor of Country Home magazine, writes with a hands-in-the-dirt affinity for the rhythms and needs of growing things. “The Peach Thief” bursts with a thousand sensory details: the sun-warmed velvet of a ripe peach, rhubarb plants with “stalks red as rubies must be,” “the hum of life” in the “tiny scrap of green” of a cauliflower seedling.

Not even a perfect peach will satisfy the hunger for affection that gnaws at Scilla. She falls under the spell of Phineas Blake, a gardener-in-training who could charm the stars out of the sky. His smile makes Scilla feel as if the sun has “shone right on her,” as if she’s been “cold all her life, craving sun,” and hasn’t known it.

For someone who’s never been wanted by anyone, the attention proves irresistible — and dangerous. Phin takes her on midnight raids of “the glass-houses,” the greenhouses where the earl’s precious fruit grows out of season, warmed by hot-water pipes.

It’s a betrayal of Mr. Layton’s trust, but when Scilla tries to resist, “that empty place inside her” starts “begging away, as starved as ever.”

Every Eden hides a snake, and Scilla feels like the serpent in this paradise. Mr. Layton will surely cast her out when he discovers she’s a thief and a liar. Tension mounts when Emily, Scilla’s protector at the workhouse, gets hired as a housemaid and recognizes her old friend in front of Phin.

What will Scilla have to do to keep him quiet? One step too far and her new life will collapse like the tree she climbed down that first night.

Meanwhile, the garden staff works feverishly to prepare for a visit from Prince Albert, Queen Victoria’s husband, who wants to inspect Mr. Layton’s innovations in the garden and glass-houses. (It’s the year before the Great Exhibition of 1851 and progress is in the air.) It’s thrilling and terrifying to watch as Scilla builds an ever more precarious trellis of lies.