When I harvest seeds from tall phlox, I put them in a paper bowl with a paper plate over the top. When the seeds are ripe, the pod will explode and split into two pieces, shooting the seed as far as it can. It cracks me up when I hear the Ping!! as the seeds hit the plate that keeps them from flying across the garage.

Do I sow the whole pod or remove the seed first?

Did I your question?

I sowed mine already, found a few brown pods. Yes, I broke one open and found just one seed. The others, I figured let them explode and scatter their seed on the other side of the sidewalk lol. So I scattered the seed pods there to balance with the nice ones on the other side of the sidewalk. I will transfer some more across the sidewalk when they're ripe to help them along so they don't all sow on the same side.

Then I'll order the colors I want from Bluestone and maybe that Blue Paradise? somewhere else. I'm done with plans. I just planted a bunch of dianthus from a packet of 10-cent seeds I ws'ed 2 winters back. About time. Nice plants, too. Had to wet the ground it's so hard. So that will fill in, planted an aster over my french drain (gets boggy there).

All the phlox species I've sown have a similar looking black seed. Apparently they are in pods, never collected them?

As for Phlox paniculata, I don't have to bother winter sowing those - they sow themselves quite nicely! Some of the seedlings come out a pink color of the species, but some seedlings resemble the mother - my Phlox David seedlings have been white so far, Tracey's Treasure seedlings are light pink, and Nora Leigh seedlings have flowers like the mother, although the foliage isn't variegated.

Well mine haven't popped open so now I'm having doubts about whether they're any good. They were dry when I collected them but maybe our hot summer made them dry up before they were filled out or something.
Terrene - My phlox 'David' has done just the opposite, several volunteers but only one with white flowers that I know of. The rest have all been the common pinkish purple color or near it. No mildew so far though.

The one I'm trying to collect seeds from is a reverted 'Peppermint Twist'. The flowers are a pretty coral pink (solid) and I just wanted to see what I would get, with my luck, probably that same pinkish purple color but it's fun to try. I also planted Peacock Purple Bicolor this year but I haven't found any seeds on it. It didn't bloom very well. I tried to root a couple cuttings from Peppermint Twist but they didn't take. I suspect it was too late in the summer. I've never tried cuttings taken from the roots and I'm afraid I'll kill it.

Thanks : )