Ok, you've convinced me to try some agastache plants, but in addition I would like to sow some A. foeniculum seeds to compare. Advice on when to sow those on the web is scarce and somewhat conflicting:
Indoors 6 to 8 wks before first frost (2 references)
Indoors 8 wk before first frost (1 ref)
Outdoors after last frost (1 ref)
Indoors Mid Feb to Mid March (1 ref)
Wintersow (2 ref) (I have had mixed results wintersowing with other flowers.)

Which sowing method/time would you recommend for these seeds in CT (Zone 6a) ?

This is a very easy species to grow from seed. I would use whatever method fits your facilities the best. They are pretty undemanding. If you start 6 to 8 weeks before you can set them out, you will have some pretty substantial plants ready to go.

Thanks Kermit for chiming in with info.

I just usually grow Agastaches as plants, but there are others who might chime in that grow them from seed.

I usually winter sow most everything. Most Agastache need warm temps to germinate. I normally will set my winter sowed ones out in April. Hope this helps.

Thanks Duane for your info!

Don,

If at all possible, start with fresh seed. I was disappointed several years in a row when trying seeds of unknown age. Once a friend sent me some fresh seeds, it was as easy as can be. I used the winter sowing method in 2011; sown Feb. 15, and sprouts by March 5. I ended up with 72 transplants!

If you're not sure about the freshness of your seeds, you might try test germinating a few by using the baggie method (indoors) first.

Best of luck to you! Once you do get a few plants going they'll reseed just enough that you'll likely never be out of them.

Thanks Chelle for chiming in!

Thanks for the advice. I'll go with the -6 to -8 week starting date, but I'll also give wintersowing a try. And Chelle, since I haven't tried these before, the seeds are all new this year.

That's great, Don.

My first attempts were with pass-along seeds, so I had no real idea of their age or of how they'd been stored. Seems like you're good to go.

Best of luck to you!

Good luck Don!