Sheriff Beau Arlen, played by Jensen Ackles, hands Cassie Dewell a canister of salt "for protection" as a housewarming gift. This is a hark back to the actor's role on long-running Supernatural where salt was one of many weapons against demons.
A young couple comes across a marked tree, and they question the red colouring rubbed into the cut--blood or paint? If it'd been blood, it would've been swarmed with flies.