How do I harvest Parsnip seeds?

I left a few parsnips from last year in the ground over winter in order to get seeds from them this year. Now, the time is either here or fast approaching and I've got no clue. I know, sad. But still true. So...help!

Parsnip stalks approximately 6 feet tall

Central Stalk - Are those seeds ready?

Surrounding stalks - still blooming and more flowers coming.

I saw on a short video online here, that this woman waited until the stalks and seeds were all dry and then cut them and shook them in a pillowslip. I probably would have done that. But then I saw other articles that said the home seed saver can get better seeds by babying the seed heads.

Basically, I gather that I should cut the flower heads when they become seeds and dry them indoors and collect them that way. But how do I know when? I mean, is that central head ready to harvest for seed? Do I just leave the others and harvest the heads as they get ready like the central head?

Anyone who knows and can offer advice, I'd be so very appreciative.

And my apologies to you all! I've not kept up with all your posts like I should with the growing season well in force and household projects that can't be put off anymore taking precedence. I'll try to visit you all, the ones I've missed, very soon to see what's up and I'll try to post more often too. :)

Garden update should post tomorrow. Wait till you see....