like pete and scott said zweefer, once a year, in the spring of the year if one reverses. like scott i don't reverse, i have extra bottom boards, i prefer to pull them and change them out to clean them up, (like to maintain them, check them, re-stain, repair, or replace) and i do it sometime during early spring months. like pete said, early spring clean it off to save the bees some work of the winter dead, from there on out, the bees are very tidy. even if you didn't, they would take care of anything on the floor of the bottom board that they can remove and carry out the front door.
capn, you don't need to clean off your bottom board, you just hived your bees. this is a great disruption to the bees and really unnecessary and your bottom board will probably be cleaner than your kitchen floor......
