100 Days. This fodder variety has been around since the 1800’s. These beets were prized as nutritious animal feed that was easy to store. Fodder beets are hardy, adaptable, and palatable. Red mammoth beets produce a large amount of edible beet leaves and a large root. They are ideal for planting in late summer for use as a winter and spring crop.100 Days. This fodder variety has been around since the 1800’s. These beets were prized as nutritious animal feed that was easy to store. Fodder beets are hardy, adaptable, and palatable. Red mammoth beets produce a large amount of edible beet leaves and a large root. They are ideal for planting in late summer for use as a winter and spring crop.