The best decoy you can use in my opion is by using the plant itself, go to walmart and buy some fake flowers, and tie them all over the plant and from the distance it just looks like a flowering bush. True story, a few years ago, we had some nice 7 foot tall and 4 foot wide plants growing in our back yard, we tied fake flowers all over the plants, and one afternoon the cops chase a dude into our backyard and wrestled him down to the ground and stood there with him for like 15 minutes till more cops came, there was a total of 16 cops in our back yard less then 12 feet away from our flowering bushes!
and they never once noticed the 6 huge northern lights. thankgod for walmart!!!!!