Police were summoned to the scene in Bretten, near the southwestern city of Karlsruhe, on Thursday morning by a worried 81-year-old man.
They said in a statement today that officers determined "the object, which really did look very like a bomb" was actually a 40-centimeter (nearly 16-inch) zucchini.
The offending vegetable, which was very dark in color, weighed about five kilograms (11 pounds). Police believe someone threw it over a hedge into the garden.