Q.How long does it take a poppy’s pod to form?
Once the petals fall off and the green “stem” (? Future pod?) grows , how long does it take before the round pod usually forms and it is ready to harvest? Do the flower/plants need to continue to be watered during this process? (They originally were only watered naturally by the rain) Thanks for your help!

Certified GKH Gardening Expert
The answer will depend upon the length of your growing season. The pods usually form at the end of their seasonal life cycle. Here's an article
that may be useful:
https://www.gardeningknowhow.com/ornamental/flowers/poppy/saving-poppy-seeds.htm