some people use both, some just the ply wood or just the fence. The fence with ply wood on top, then weight will cover about 1/2 the seed to 1/4" deep or less. If the soil is moist, its sometimes helpful to go over it again with just the weighted plywood to press in the soil. If the plot is small enough, some people just drive back and forth over it with their truck/jeep or ATV.
