One hive in the yard is bearding halfway up the front of its lower deep box. Supers were taken off 7 days ago and it has a deep, med. and med. for brood. I even put 3 frames of foundation only in the top deep when I harvested honey so they would have something to do. Shall I replace foundation with drawn comb so they can simply fill them with fall honey? Why might this one hive be bearding and should it concern me(only mid 70s today)? This hive has no history of bearding over the past summer.
Bearding is common after harvest. When you have a few supers besides your brood box full of bees and remove the supers the bees that filled those other boxes have to go someplace, hence the bearding. A slatted rack would solve your problem, if you don't have one don't worry. The older foragers will be dying off soon and the over population will correct itself.