the general rule of thumb is old man to young maid...crude - but you want pollen that has fully opened, and is looking fluffy. you want a flower that just recently opened - no more than a day open. sometimes the pollen opens right away, sometimes it takes a day to fully open ...

Thanks..When the flower falls off and the green pod remains, does the brown dot in the middle of the green pod (when you look down in it) mean it's fertilized and should remain on the plant?

after the flower falls off - the pod should start swelling and growing. expect to wait about 6 weeks for the pod to ripen. it will crack open when its ready to harvest. I cover with an organza bag so that i can let the pod open up a bit before taking off the plant. it helps the seeds fully mature.