I had this happen to me a couple years back. Had about 20 plants in the woods behind my house. I went to check on them one day and every last one was gone. I was kinda freaking out at first cause I though it might have been cops ya know? I never heard anything so I decided it was just some jerk stealing my stash. The next year I got smart and planted about 30 plants, in groups of two all over my land so that if they found them again they wouldn't find them all. It was a LOT more work taking care of them since I had to walk a lot more but worth it. By the time harvest rolled around i had 18 plants still. A few I'm sure were eaten by deer or what not but I salvaged the rest and might i add that it was some righteous bud.