Any time. Since it will germinate - slowly - whenever the conditions are right just as it does when it reseeds itself. Many over on the Herbs forum talk about seeding it in the winter even.

Dave

Great, thank you!

NOW

I winter-sowed it and it is already up and showing true leaves. Parsley, with its slow germination, is ideal for winter-sowing. There's a whole forum about it here if you are interested. One of the easiest ways to start many herbs and vegetables--flowers too!

Hepatica

Thanks, I'll take a look!