I have always liked something like
No Trespassing Acres
Keep Out Farms
No Solicitors Ranch
Of course, you could just use Adam's Acres. Or in light of the REALLY great grips you make- Brown's Woods, or Adam's Woods. Or for apocalypse fans, Adam's BOP or Browns BOP (bug out place).
We named our place Fred. If someone is asking us to do something we would rather not do (Mary Kay Party, etc) answer was Sorry- we have plans to spend the weekend with Uncle Fred.