I like being new and innovative, and because of that I don't love to include features that are very similar to what we see elsewhere on the web. Having said that, I know that other databases including growing reports based on their location, i.e. "This plant has been reported to grow in the following cities:" and it seems like it's something we might really want to add at some point.
So, should we add that feature to our database here? It would be trivial for me to add it in, and I can think of some pretty fun features we could do once we get enough data inputted. We could even make maps with buttons that show where in the world each plant has been reported to grow well, etc. I can also, of course, easily ensure that the zipcode you enter matches the actual correct city.