In a large bowl, combine pineapple, mandarin oranges, and cherries.
Add coconut, marshmallows, and nuts (if using).
Gently stir in sour cream or whipped cream until well blended.
Cover and refrigerate for at least one hour to allow the flavors to blend and the marshmallows to soften.
Stir gently before serving. Serve chilled for a refreshing and delicious experience.
