Four very different women, all wanting to escape cold and dreary London for different reasons, come together to share a month's holiday in an Italian medieval castle. There’s timid Lotty Wilkins, terrified of her domineering husband; sober and religious Rose Arbuthnot; rigid and judgemental Mrs Fisher; and the breathtakingly beautiful but disillusioned and unhappy Lady Caroline Dester. They are lured to the castle by the advertised 'wisteria and sunshine', but they end up finding there so much more than they had bargained for.

It began in a women's club in London on a February afternoon. A discreet advertisement in The Times, addressed to "Those who Appreciate Wistaria and Sunshine..." lures four very different women away from the dismal British weather to San Salvatore, a castle high above a bay on the sunny Italian Riviera. There, the Mediterranean spirit stirs the souls of Mrs Arbuthnot, Mrs Wilkins, Lady Caroline Dester, and Mrs Fisher, and remarkable changes occur.

When four women leave their drab lives behind to go on holiday in Italy, their lives are changed forever by the Mediterranean. Mrs. Arbuthnot and Mrs. Wilkins, while part of the same ladies' club, have never spoken. Lady Caroline Dester and the elderly Mrs. Fisher join their holiday so as to mitigate expenses. As these women come together and learn more about themselves than they ever thought possible, they reveal their true personalities and the backdrops of their lives that tend to hinder them.

The discreet advertisement in The Times, addressed 'To Those who Appreciate Wistaria and Sunshine', offers a small medieval castle for rent, above a bay on the Italian Riviera. Four very different women - the dishevelled and downtrodden Mrs Wilkins, the sad, sweet-faced Mrs Arbuthnot, the formidable widow Mrs Fisher and the ravishing socialite Lady Caroline Dester - are drawn to the shores of the Mediterranean that April. As each, in turn, blossoms in the warmth of the Italian spring and finds their spirits stirring, quite unexpected changes occur.

This is a journey of both escape and discovery for four exquisitely different women, a month of bliss and privacy for four weary souls. Their refuge on the Italian Riviera provides the perfect backdrop for a story about the search for spiritual harmony within and without.