You now have two framing units, one for each end of the raised bed. Next, cut four 1x3.5 boards to a length of 5'. Set the framing units upright, 5' apart (propping them up with watering pails or anything you have handy).
Lay the 1x3.5 boards across the framing units, spanning them. Space them slightly, to provide drainage and aeration. Work out from the center, as you'll want to leave 2" free at the sides (enough room to fit the 2x4 you'll be using in Step #8). Pre-drill holes through them and screw them into the supporting 2x4 braces in the framing units.
You now have the "floor" or bottom of the planting bed. In Step #6 we begin on the walls....
