From the "Seeds" forum Echinacea would be a first year flowering perennial from seeds.
Which other perennial plants can we grow from seed and have flowers the first year?
Campanula carpatica?

Agastache rupestris

Blanket flower

Chives

I've had delphiniums flower the first year.

Good---by next season I will have a good list of first year flowering perennials.

Oh, and Oriental poppies!

Do orientale poppies flower the first year for you?
I have not seen that?
When do you start them to get flowers the first year?
You are a little warmer than here.

Here are a few that I trialed last year. The ones marked with an asterisk have assuredly survived the horrible winter we just had; the rest aren't showing obvious signs yet, but it's still very early.

Penstemon (Penstemon x mexicali 'Carillo Purple')*
Carpathian Bellflower (Campanula carpatica)*
Hedgerow Cranesbill (Geranium pyrenaicum 'Bill Wallis')*
Current-leaf globe-mallow (Sphaeralcea grossulariifolia)*
Cottage Pink (Dianthus plumarius 'Velvet 'n' Lace')
Maltese Cross (Silene chalcedonica 'Dusky Salmon')*
Blackfoot Daisy (Melampodium leucanthum)
Hyssop (Agastache aurantiaca 'Sunset Yellow')
Seed Box (Ludwigia alternifolia)
Alpine Catchfly (Silene suecica)

Thanks! Chelle!

Oops, sorry Caroline, for some reason I thought we were in similar zones. Most of these are listed as hardy to about zone 5. I guess you could still check them out though.

Yes I would check for zone differences.
But sometimes a plant will surprise us and be more hardy than what we think.

I'm finding that to be true, too; especially with the more natural type plants.

I have tiny starts of my oriental poppies in the greenhouse now. And I think this is about the same time I planted the first ones, a couple of years ago. Those (Princess Victoria Louise) definitely bloomed the first year. Not a whole lot of flowers because they were still a bit small. Lots of flowers last year, tho, which is why I'm starting a couple more varieties, Royal Wedding and Queen Alexandra.

I have the oriental poppy : papaver bracteatum, a big red one, sown as a winter sow.
But I don't expect flowers until next year.