Rosemary Boxer goes to visit her friend Daniel Kellaway, who suffers from eczema, to receive a cash grant for her university but is asked by him to investigate the dying trees in the grounds of his mansion home. Laura Thyme has left her home after being cheated on by her husband and goes to see her friend Sam, who is later killed in a car accident whilst driving home one night. After meeting one another and forming a firm friendship, Rosemary and Laura begin to investigate into the accident and the dying trees.

The newly formed gardening duo 'Rosemary and Thyme' are called to help pop star Nev Connolly design and create the gardens for he and his wife Patsy's new house.

Rosemary and Laura are called to Vincent House Health Spa to rejuvenate 'The Dell' a water cascade designed by a women named Fenella Gothe, who has since died.

Rosemary and Laura are summoned to Bowden Grange Language College to solve the mystery of random dead patches appearing on the lawns.

Rosemary and Laura travel across the country to assist Rosemary's old friend the blind Professor Mullins, who has asked them to look into the odd death of random patches of plants on his allotment.

Rosemary and Laura go to the village of Baffington where they are asked by the vicar to clean up the local churchyard in time for the upcoming Medieval Fayre.