To get maximum hunting season attraction, plant food plots around Labor Day in the Northeast. Later below the Mason Dixon. You want the plants to be at their most palatable and tasty when you are out hunting.
Planting brassicas too early will make the leaves less palatable in October. Oats planted too early will bolt and not be desirable until there is nothing else to eat. Winter wheat and rye can be planted anytime in September. For the best root system development and leaf forage, early September is a good time to plant.