Chaste tree seeds: so many questions!

The backyard of the house I moved in a couple of months ago has this beautiful chaste tree (Vitex agnus-castus), with purple flowers. Right now, it's full of seeds, that do not seem ripe to me yet (they look yellowish-green). Can anyone give some advice on how they look when they're ready? Would any of you be interested in having such seed? They are so many, it would be a pity not to try harvest and share. Before sending such seed to other people, should I test them first for germination, so I don't make a goof of myself? How do I germinate them?

Thank you for any answers you may have!
Alexandra

I live in PA. Four years ago I started three chaste trees(shrubs) using the winter sowing method. I later found out I probably planted them out of my planting zone. They are still growing. I gather my seeds in the fall after they are brown. This is a photo of mine from a few weeks ago. I have one purple and two pinks.

DEMinPA

Thanks, DEM! What's wintersowing?
My neighbor has a white one, just saw it! I think I should talk to her... After the rains here, they kind of started to rebloom!