Normally in zone 6 PA the seeds mature in June. You can always place some nylon stockings over the ends of the seed pods and fasten with a twistem if you believe the seeds will fall without your noticing them.

When the first pods show signs of splitting(under gentle pressure twixt finger and thumb) then look to harvest all those pods in similar condition. Seed should not be white(unripe, although may have partial germination); part white, mostly grey and part black is best. If you leave them to ripen and fall from the pod, they will all be black or nearly so, again good germination but difficult to harvest. I get near 100% germination from mostly grey seed, split gently from the pod just a few days before it would naturally fall. The little socks are a good precaution against the mice and whatever other critters that like to eat the seed, as even daily attention to harvesting time is not enough to prevent the nocturnal foragers!!!

Cheers Greenmanplants

I didn't realize they would still germinate when they're gray. I'm glad you told me that. I think I've been waiting longer than I need to with my foetidus. I'll check the exchange forum later this year for fancy hybrids. Thank you