Cook bacon until crisp in a large saucepan. Remove bacon, reserving drippings in pan. Drain bacon; set aside. Cook onions and garlic in drippings over medium heat until tender.
Add water carefully to green onion mixture and bring to boiling. Add turnips, pork hock, sugar, salt, and ground red pepper. Cover and simmer for 45 minutes. Remove pork hock and set aside.
Meanwhile, wash greens thoroughly in cold water; drain well. Discard stems and any damaged portions. Tear up as desired and add to green onion mixture. Cover and simmer for 15 to 20 minutes or until greens are desired doneness.
Remove meat from pork hock and chop meat. Return meat to greens mixture along with the cooked bacon. Heat through. Serve with a slotted spoon. Sprinkle each serving with a little vinegar, if desired. Makes 6 (1/2-cup) side-dish servings.