Very enjoyable post! Have you ever planted an garden? It's interesting to consider food bearing plants compared to weeds. Evolution would seem to be entirely selfish so why in the world would a tomato or a carrot or a potato evolve. They spend all of their energy making very nutricious fruits that do them no good at all. Compare that to the weeds that grow along with the plants. If you don't keep up with the weeds the food bearing plants don't have a chance. Why would a plant bother to evolve that way? Weeds have all the advantages. They do now work in the sense of bearing fruit, they spend all of their energy in laying around, sucking up all the nutrients and sunlight and reproducing. They seem to be all genetalia in a plant sense. Kind of reminds you of some people doesn't it. Evolution would favor them and destroy plants that bear fruit.
Well, a Darwinist would argue that apples (for instance) evolved so that some animal would come along, eat them, and then eject the seeds a day or two later, perhaps miles away. That wouldn’t work with the kinds of seeds that animals deliberately ate for food and thus destroyed, but if animals could be fooled into eating the fruit and incidentally carrying the seed to new fertile ground without being aware of it, it would help the plant to spread. Beneficial for all concerned.
Then different kinds of apple trees would compete to see which could produce the best tasting and most popular variety.
Of course, God would do the same thing, for the benefit of both trees and apples, so this Darwinist theory doesn’t displace the story about the origin of different plants that bear seeds and fruit in Genesis. In fact, I suspect that this theory can explain why apples would get bigger and better over time (and much more quickly when humans started breeding them) but it doesn’t really explain how they came about in the first place.
A number of plants spread their seeds over a wide area by having the fruit eaten by animals. The seed is indigestible and passes out of the animal's digestive system a long distance away from the plant that produced it, conveniently surrounded by a nice pile of fertilizer.
For the case of potatoes, they are perennials. The underground part contains nutrients that allow the plant to grow quickly in the spring, getting a head start on other plants in the race to establish itself.
Also, keep in mind that these plants have been cultivated for thousands of generations -- only plants which produced food would have their survival enhanced through cultivation by humans.