My favorite source of wildflower seed is Prairie Moon Nursery. They are reasonable and have good germination rates. For milkweed, I buy from Butterfly Encounters. A little more expensive than some sources, but seeds are fresh and have great germination rates.

Sandy

Here is a link that might be useful: Prairie Moon Nursery

thank you

Another good source is Everwilde Farms. Lots of natives and some non-natives. I've used them and their seeds are really good.

If you want seed packs with lots of seed, e.g., from 250 up to thousands, use Hazzard's. I ordered from them this year because small packets are so expensive IMHO for 25-30 seeds. A packet of 250 seeds of Asclepias physocarpa (aka Oscar Milkweed aka Family Jewels) was $8; $6 for a pack of 1,000 Cut & Come Again Zinnias, for example. Very GOOD seeds, too. I'm attaching a link to them. While they are a wholesale company, they sell retail.

Susan

Here is a link that might be useful: Hazzard Seeds

My favorite place to get seeds is here on the seed exchange forum or right on this forum or from friends on the winter sowing forum. Many of us collect seeds for ourselves and always have more than we can use. Just mention what it is you are looking for and you'll often get an offer. Gardeners tend to be quite generous when it comes to other gardeners.

Martha

Hi button20. ebay is also good. just make sure you buy from a seller with good feedback. The only caveat about getting seeds from the exchange forum is that there's more of a chance that you'll get the wrong seeds OR seeds with a low germination rate. most of my dealings via the exchange forum have been good, but I have gotten bad seeds a couple of times.
Good luck, Tony

Thank you everyone for this very useful information, coolbutterfly: I will have to check ebay!