Steam the beet(s) by cutting off the greenery and standing upright in a saucepan with lid. Fill with about an inch of water and bring to a boil. Lower the heat to simmering and cover for 40 minutes or until tender. Spray or grease a regular sized loaf pan or three mini loaf pans. Coarsely chop the cooked beets and process in a blender until they measure one cup. Add the water and combine. In a large bowl mix sugar and margarine using the low setting of a hand mixer. Add eggs and beets and mix. In a medium bowl combine the two flours, soda, and salt. Gradually add to wet ingredients, mixing after each addition. Fold in the nuts. Bake large loaf for 55-65 minutes. Bake mini loaves for around 30 minutes.