This is my first year growing Cerinthe (blue shrimp plant) I am growing the strain "Pride of Gibralter" from seed and it's pretty much run it's course, I got thousands of beautiful blooms and would love to grow them again next year- but I havent found a single seed yet and they are pretty much done now...! I see tons of little tiny black dots on the plant I can wipe away, but the seeds are about the size of an infants nail and I would notice them. I look everyday but have never seen a seed, do I need to cut the flower to get it to produce seed? I am growing 3 in different pots and would love to gather as many seeds as possible to trade/sell. I know they tend to reseed, however mine wont because they are in pots on my concrete patio...

Any advice would be appreciated! Thanks in advance.