In a post-war London square, Olivia Chesney Flora Robson is too ill to leave her home and can only wave to the neighbors from her window. Among them is Lovejoy Mason June Archer, a neglected girl who finds solace in a secret garden she creates on a bomb site. She buys grass seed with borrowed money, strips a net from a baby’s pram to protect the sprouts, and even pockets a little money from the church’s candle box to buy a garden fork for her growing green space.
Lovejoy is looked after by the Vincents. Mr Vincent David Kossoff runs a polished restaurant and is very kind to Lovejoy, while his wife Mrs. Vincent Barbara Mullen keeps a careful eye on her visitor’s rough edges. Lovejoy’s mother, an actress away on tour, returns with a lifestyle that raises questions, and when she visits she brings “company” such as Col. Francis Baldock Cyril Chamberlain, whom Lovejoy is told to call “Uncle Francis.” Despite the kindness, Mr Vincent grows uneasy about Lovejoy’s presence and asks her to leave.
A gang of boys targets Lovejoy’s garden, and one boy, Tip Christopher Hey, returns her fork and suggests moving her patch to a bombed-out church. They form a tentative friendship, and Tip makes Lovejoy pay a form of penance for taking money from the church by helping her learn to respect the new site. Back at the restaurant, Mr Vincent buys two fancy plates for dessert, but Mrs. Vincent reminds him that they must pay their bills, underscoring the precarious balance of care and practicality in their lives.
Meanwhile, a wealthy couple has plans for the bombed church. The woman gives Lovejoy a shilling inside the church, and Lovejoy is impressed when she drops it into the candle box as part of her penance. The couple then visits Vincent’s restaurant, where they treat Lovejoy to a ride in their car and present her with a miniature rose to plant in her garden. An old man offers Lovejoy more seedlings to nurture, while Tip and the child Sparkey steal earth from a private garden square, drawing the ire of the adults.
On a rainy night, Tip brings Lovejoy and Sparkey Brian Hammond to the park to steal more earth. Lovejoy is arrested, and the police realize her mother is away in Canada and has remarried, leaving Lovejoy with little chance of a normal life under her old circumstances.
Financial troubles hit the Vincents hard, and they must give Lovejoy to the Home of Compassion care home. Desperate, Lovejoy appeals to Olivia Chesney Flora Robson to help. Olivia, feeling she has wasted her life, decides to draw up a will to open a new restaurant in the West End that the Vincents would run, on the condition that they look after Lovejoy.
The bombed church is eventually pulled down, and Lovejoy leaves the care home to rescue her beloved rose. Olivia dies before signing the will, so her sister Angela Chesney Catherine Lacey inherits the money. Lovejoy returns the rose to Olivia’s house, unaware of the death, and Angela is deeply moved, choosing to honor her sister’s wishes by establishing the trust. Lovejoy then goes to live with the Vincents, and the couple begins preparing for the new restaurant, hopeful for a brighter future for Lovejoy and their small, renewed circle of care.