Be patient, maybe the bees haven`t been busy enough yet. The first signs of flowers setting will, obviously, be in the lowest ones on the plants. I usually grow Bunyards, but this year left my ordering too late and could only get green Windsor Longpod, which are as tall as yours,but hardly a flower in sight. Don`t forget to nip out the tops as soon as the flowers start setting to avoid blackfly infestation.