Pearl Nolan's coastal allotment has always been a quiet haven – somewhere for her to relax and cultivate special ingredients for her restaurant, The Whitstable Pearl. But a sudden clamour for allotments by the DFLs – Down From Londoners – causes tension in the local community when the council decides to accommodate them by dividing existing plots into smaller parcels. The harmony that once existed between holders of land previously blighted only by slugs and caterpillars, soon transforms into a bitter turf war as a pushy DFL tries to take over by forming an Allotment Association – with herself as its chair.

When anonymous complaints are submitted to the council about each of the local allotment holders – apart from the DFLs – Pearl's services as private detective are called upon to discover the complainant but before she can do so, what began as a tiff among the turnips soon becomes a hunt for a killer when gardening tools are put to murderous use ...