The sign when to collect vft seeds is allowing the whole flowers to dry. usually , after pollinating all the flowers, the flowers will close, then the flower pod will swell a bit. when this happens just wait. so the flower pods will swell, after a couple of weeks, they will begin to shrivel. just inspect each flower pod closely each day. they seeds will be revealed on their own, they will not spread all over the place if they are harvested in the right time. once the flower pod shrivels, it will reveal the seeds on its own, then that's the right time to collect seed. i am awaiting for my flower pods to reveal their seed. :) i already pollinated over.. 40 + flowers! and i still need to pollinate more. good luck.

Merci-beaucoup...thank you for the quick response Sharon.My poppies only started blooming about three weeks ago, so I guess that I have to wait a little while yet. Ricky

A little chaff doesn't bother me. Whatever doesn't blow off the top (if the seeds are big enough to stay put) is fine.

Not at all a common practice so it will be difficult to find anyone with actual experience doing this. Not only will you not get the same potato if the seeds even grow, but it will take at least 3 years before you can get a crop of harvest size. The seeds will grow a plant which when planted next year will develop some small marbles, those marbles are then planted the following year (assuming they survive storage. The 3rd year you might get a few with some size but most will be small seed potatoes to plant again the following year. So are you sure you really want to invest all that time and effort when you can just buy YG seed potatoes and actually get potatoes to eat? If so then, you must let the seed pods fully mature on the vines. They won't mature if the vines are pulled. How long? Can't say but you will have to wait until the vines are dry and brown. Dave