The native wetland plants that produce cranberries start growing in May. When they are ready to be harvested, farmers flood their bogs with water and send out a picking machine to shake the berries from the vines. Then more water is added to the bog, and the freed cranberries float to the surface.

Despite its deep roots in Thanksgiving history, this dish remains one of the most polarizing items on the table today.

There, the berries are run through a system that separates them from leaves and vines and are transported to processing plant, which eventually turns them into sauce, juice or sweet ... a second-generation cranberry grower, on the edge of his bog.

Weeks before Thanksgiving, some of the cranberries on dinner plates Thursday are floating on the Rocky Meadow bog in southeastern Massachusetts. The cranberries have turned this pond pinkish crimson.