Plymouth Rocks are friendly and are great producers of large brown eggs, laying 250 – 300 eggs per year. Developed in New England, Barred Plymouth Rocks, Barred Rocks, or just Plymouth Rocks, are a very popular breed of dual purpose chicken. The Plymouth Rock is well-adapted to cold winter weather, and continues laying eggs during the winter months. This breed does best when allowed to range freely, rather than being confined. Expect a friendly and docile temperament from these smart birds.