From personal experience, this is absolutely true. I lost 34 plants once, but found they missed two that were well away from the others. I was still pissed, but at least I had the fruit of two of the girls to help me through it.30-40ft. spacing is not good enough, if someone finds one there, they WILL keep looking! space each little patch atleast a 200 ft. apart. That way if they find some they most likely won't find it all.