Is there something wrong with that?
You don't have to sray EVERYTHING down!!!
I think it is actually a superior way of growing plants, I am a huge 'contained eco-system' buff.. when I kept my planted aquaria I had everything from shrip to fish and malaysian trumpet snails to 'perfect' the environment, where as a lot of people would have coniptions if they lost power to their tanks (bio-filters die and other nasty stuff) I would never worry about that, my plants were so healthy that they would litterally bubble oxygen right of the leaves... you could SEE photosynthesis happening through the plants resperation! Sounds crazy, but true! The water was saturated with Oxygen, so rhather than the plants O2 diffusing into the water, it would bubble off, like a freshly poured sprite.
When I build my greenhouse, well, my dream greenhouse, it will be completely landscaped within, you would just have to be in my mind to understand... but waterfalls, and all sorts of fun stuff, all with a purpose for making the ecosystem complete.