For seed I've had good luck with Thompson&Morgan and Chiltern Seeds (UK). When I was growing primula from seed I discovered they needed light to germinate so surface sow without covering them with soil or mix.
I don't think either of these places are selling the 'Cowichan' strain now but google Barnhaven Cowichans for some eye candy. I had a lot of these at one time, quite a few of the deep inky blue ones, they almost made me drool they were so gorgeous :).

Annette

Another source for primula seeds is Hazzard's. They're a wholesale seed supplier but will accept orders from anyone. I've ordered other seed types from them several times and found the shipping to be fast & germination is excellent.

The link I pasted below is what I copied from page 8 of their perennials O-P.

Here is a link that might be useful: Hazzard's seeds

Cracking, you might like to try the following two seed exchanges:

North American Rock Garden Society - http://www.nargs.org/

The American Primrose Society - http://www.americanprimrosesociety.org/

Both offer a wide variety of primrose species. For named cultivars, the APS is better, but NARGS' primrose packets are generally more generous in numbers of seeds.

A very informative series of threads on growing primroses is here - http://cubits.org/irisforum/thread/view/32258/

Great wintersowing propagation thread - www.wintersown.org

For a more comprehensive source on which primroses prefer cold and which prefer warm temps for germination - http://www.onrockgarden.com/

Good luck and I hope you get some great surprises

Very cool. Thanks so much you three! I was googling pics and every year I sort of pick a new plant to obsess over and thought I'd try primulas after seeing some amazing clumps on a post :)