"...defined yet defied categories..." great phrase!
I like the idea of broader categories, and agree with Dirt that the specific flower categories were a tad tiresome (no offense to anyone, all the photos were beautiful). Seasonal flowers would be difficult given we are in so many different zones. But perhaps shape of bloom - trumpets, daisies, bells - could be a consideration, although that also lends to a bit of the boredom factor (too much of the same thing over and over).
I like the idea of vines as a category, wide range there.
I loved the fox in the fruit/vegetables and would encourage a wildlife category (to eliminate everyone's dogs/cats) as long as they are in a garden setting. And perhaps reptiles.
I didn't notice if we had the same categories last year and/or if we had fewer or more this year.