I think this would be helpful for those of us in tropical areas that aren't really covered by a zone that is dependent on how cold it gets. Cold is not a limiting factor but rainfall and heat and day length are good ones. I might add whether or not there is a pronounced wet and dry season that requires protection from rain at times and irrigation at others.
Oh, and avg humidity, that can make a big difference in whether something can thrive in heat or not. Was that already up there and I missed it? Not having a period of chilling means there are a lot of plants that you can't grow, maybe a check box for that?
