Back to the subject of this thread - I think we all just enter photos where we think they best fit. I have the same quandry re native plant v. tree/bush. Hopefully the take-away will be more categories in the future. Although I really like the idea of more frequent contests to coordinate with the plant weeks. We could then split the smaller focus contests into different categories and really immerse ourselves in a targeted group of plant photos.
I certainly found that my cache of photos were taken mainly for identification purposes and thus are mostly rather blah closeups of the bloom, the whole plant, emerging, and at season end (not much composition in any of these). I have most of my plants well documented this way, and will now strive for some more artistic shots. All in good time...the new Photography forum is certainly helpful in that regard.