New York,
United States 
I just had to cut down most of my giant alliums due to severe storms. The seeds heads are still green. Can I still dry them so they're viable for next spring planting ? I love collecting seeds and planting them again. It feels more natural and productive to me than buying seed packs that don't always grow...or don't grow true to size. In fact one of the giants turned out to be the size a a salad plate ! Planted from the same bag of bulbs. Woo hoo !
18 Jun, 2014
Answers
The bulb will be OK and grow next spring/summer. I would place the flower head in a paper bag and let it dry. Any small black seeds produced will collect in the bag - just throw them out onto a prepared site in winter and let them grow if they grow.
19 Jun, 2014
Previous question
Try it and see - nothing venture nothing win, but I'd be surprised. I guess it depends on whether the flowers had been fertilised.Isn't there even one plant left with the seed head still on it?
18 Jun, 2014