If the seeds were held above ground and remained mostly dry I would do a damp stratification period (for species that require stratification).

can you be anymore specific on what plants you are asking about....

and do you happen to know .. or can find out.. how cold it was this winter in your area ...

and perhaps tell us your location ... big city name ... z6 is about half the US and varies wildly .... zone is just the min winter temps for one moment in time during said winter.. so it doesnt tell us much ...

usually you can figure out the answer.. by learning what self seeds in your yard ...

all that said.. harvest some.. and try seeding them into flats or pots.. that are outside ... do it the easy natural way.. rather than complicating it all dragging them in the house ....

ahhh... what the heck.. if you have room indoors.. try some there also ...

over the decades.. i have found.. that i remember my little maniacal experiments .. much easier ..... as compared to what i read on the web ....

ken

Yes, they will. It is like it is in Nature. Nature never needed human help with growing plants on this planet.

But in nature, do the seeds held above ground without moisture germinate or just the seeds that drop and have ground contact? I agree with Cecily. But I think it depends on the species.

Sure, they will not germinate when hanging on a tree.

Ken, I'm near Kansas City. I was thinking specifically about Echinacea and Rudbeckia because that's what I have, but it got me wondering about other plants and trees too.

I did experiment this year by winter sowing white bud tree seeds that I harvested off a tree at the park last month.

I've grown both echinacea and rudbeckia without stratification. Stratification may increase the % germination, but you'll get plenty of seedlings without doing it.