Combine first 4 ingredients in a large bowl; toss gently. Set aside.
Combine ginger, marmalade, and orange juice in a small bowl, stirring well. Set aside.
Place beets in a single layer in a shallow roasting pan or jellyroll pan. Bake at 450° for 12 minutes.
Remove beets from oven, and brush with ginger-orange mixture. Return to oven, and bake 10 to 12 additional minutes or until tender.