"The bench frame and top are made of 2-by-6 decking. (We used redwood, but you could substitute cedar or pressure-treated lumber.) For a comfortable seating height, choose pots that are about 18 inches tall and wide (no wider than 19 inches for this bench). Look for thick-walled, wide-lipped pots that have been glazed (that is, hardened); avoid unfired terra-cotta. For safety, lift bench top periodically and check pots for cracks."