k man sorry i didnt get back to you earlier, i had alot goin on today.
n e way, i was reading my bible and found exactly what you need, if you have people that can see right into your back yard they wouldnt know.
heres a pic out of the book, the print is too small and this cam is too shitty so ill just type out the materials and shit.
quote under pic: this small greenhouse is covered with corrugated fiberglass. a vent on top is all the ventelation necessary. enough light penetrates the fiberglass to foster plant growth and keep out of public view.
instructions, make a wood frame with a 2 foot high wood box, about 8 feet wide and long enough to fit the amount of plants you want, build the frame structure inside that, cover with heavy clear plastic like a traditional greenhouse, after that put up the corrugated fiberglass over the plastic, flush with the wood box you started with, if you have the highest side of the greenhouse 5 feet high (7 if you include the 2 foot just wood at the bottom) and the lower opposite side 3 feet high (5 if the 2 feet of wood is included) the center area will be around 6 feet high, this will be fine for plants that dont usualy grow really tall. just make sure you have a vent area cut out of the top, like in the picture.
hope i helped, good luck and good growing! if you do something like this i want to see it done.