In a large bowl, add the pineapple, orange, and coconut.
Add the sour cream, and fold to combine.
Add the mini marshmallows, and fold to combine.
Refrigerate for 2 to 3 hours before serving.
Notes
You can eat this right away, but I like to let it sit a minute. The sour cream has time to get sweet that way, and I like the softer texture of the marshmallows.
Take care when stirring the ingredients together so that the mandarin oranges don't fall apart.
The fruit has lots of liquid in it so its helpful to let it drain for a while before making the salad.
There are a ton of variations of this salad. Don't be afraid to try some others to find your very favorite!