Cast iron cookware does not have to be seasoned prior to use; however, it is recommended. Seasoning creates a non-stick surface and protects the cookware from rust damage.
SustainableBabySteps.com reports that cast iron is the most eco-friendly type of cookware available. It can last for generations, has a natural non-stick surface and is easy to clean. To achieve these benefits, the cookware has to be seasoned. SustainableBabySteps.com recommends seasoning with saturated fats, such as coconut oil or bacon grease, for healthy alternatives to vegetable oil. Over time and with proper care, continued re-seasoning is not necessary, as the cookware retains its protective coating.