I hope this is helpful for everyone or maybe you all already know and I am just wasting my time. I found out that when you take any of the tours (bug hunt, balloon pop, etc.) on the tropical island you can pick up any of the flowers or fruit you find on the tour. After the tour you still have them and can be put in the box to go back to your town. This is a really easy and quick way to add a ton of flowers and fruits to your town in a hurry. I got three non-nativd fruits for my town while doing tours. Hopefully this is helpful to everyone!