Adiel's got it. Mennonites = Knaus Berry farm. They have excellent shakes as well, just as good as Robert.
There are plenty of other spots to get fruit, however usually they specialize in only a few. Going Bananas for....bananas! They also have other fruit, depending on what is in season, such as lychee, canistel and a few others. Lara Farms usually has mamey sapote and sapodilla. Even Pine Island Nursery has fresh fruit available. There is also a fruit & veggie stand across from the Fruit & Spice Park on 187th Ave. Many locals will sit on the side of the road and sell what they have fruiting on their property, but more so during the summer (mangoes, avocados, lychee, longan, dragonfruit, etc.) I also know a guy that sells jakfruit if anyone "needs" one.