Using plants for exterior shading of windows...  

I have always been bugged that we Americans (can't speak for the rest of the world) tend to put all our sun blockage on the inside of windows, so that the window glass (regarless of how many insulating panes are used) is left to be baked by the afternoon sun and turn our houses into boxes that require airconditioning even on only moderately warm days.

I've experimented with hanging green nylon garden netting--the stuff used to screen plants and customers from too much sunlight at nurserys--six inches from my large windows with afternoon sun and have been impressed with how much just this simple technique reduces the need for monkeying with new windows and wall insulation. I'm convinced that if one hung this stuff six to twelve inches from the side wall of an entire house here in California (where we have little humidity to contend with) air conditioning would probably only be needed one or two hours per day max on the peak hot days and often not at all. If I were designing a contemporary modern house right now it would be a glass box with a nylon net 12 inches from the glass surface covering the entire glass box. Call it Christo meets Philip Johnson at the green party. But this is back ground.

My question is: has anyone experimented with any kinds of green shade plants that open during the day and close at night. If one could find a type of vine or plant that would grow on a lattice outside a window and open in the afternoon and close at night it would be just about the best of all possible worlds for a home sun screen. It shades the windows in afternoon sun and fills the window area with enriched oxygen. It takes some water, but what say we divert the grey water from the washing machine and use that to keep the plants satisfied.