Peel rutabaga and cut into 1/4-inch cubes. They should measure about 6 cups. Cover with water in a large pot and set over high. Bring to a boil, then reduce heat to medium. Gently boil until tender, 25 to 30 min. Drain and return to burner set over low.
Microwave milk with butter, salt and cloves until warm, about 2 min. Gradually add to rutabaga while mashing.