I also have some new blooms coming up now from seed from the ones i pulled earlier this year.Personally i think you would be safe to plant them now.My sweetpeas are also coming up again as well,and they just finished blooming a couple months ago.I just let nature do her thing,and i've not been dissappointed.

Oh for reference as to where i am,i'm in Oceanside along the coast.HTH
Kathi

I don't sow my nastirtiums, they sow themselves. If there are seeds in the ground and you water them they wilill grow and flower. After they are established, if they aren't flowereing, you are watering too much. These are tough little buggers. If you are in Southern California and have a half day of sun or more, you can plant those seeds whenever you want to, and they will be happy! I dug up some a few weeks ago, and the new ones are already coming up!
I have flowers year round, 2 miles inland, but still have marine layer mornings. Nastirtiums make the sweetest little bouquets. Depending on the jar or vase, they can be homey or elegant.
Good luck, these really are fool proof!

Nasturtiums are like callas, Zantedeschia aethiopica. They like cool soil, and once the ground heats up, they're outta here. If you have a morning sun, shaded spot and offer regular water, they'll stick around a good long while.

We are 25 miles from the coast, at the very edge of the SF Bay fog belt. All the nasturtiums are now yellowed and fading, even in the backyard where two massive trees shade it from 10a onwards.

I sow the Alaska variegated and the really dark red nasturtiums every year. They're not as vigorous as the standard variety so they don't return as well. I usually do it around mid-December, when the ground has softened up with some good storms. But a month or so either way doesn't seem to make much difference.

Thank you for your comments. I love growing Nasturtiums and know they freely self-sow. I'm just wondering when others sow theirs. I'm gonna stick my new seeds in the ground next weekend.

Thanks!

When the winter rains start is best. They like cool weather. I think it is too early. The heat of Sept/Oct will fry them pretty good.