I think maybe someone on the annual forum might know. I put out all of my spring blooming annual seed between October and January.
Renee

If you get frost where you are,or the night time lows drop much below 40f, I'd suggest waiting until spring. Nicotiana prefers warm temps for best growth and isn't usually planted out as a winter annual unless you have winter highs into the 70's and 80'sf.

In so Cal, unlike most of the rest of the country, we have warm season annuals and cool season annuals. Nicotiana is a warm-season one, so wait until late winter.

Cool season annuals are pansies, stock, snap dragons, etc.
Warm season annuals are marigolds, zinnias, cosmos, etc.

Most of the books and seed companies and magazines and the like are NOT here in Southern California, so the seed packages say something like "Seed as early as soil can be worked in spring..." To which we say, "Huh?" Because soil is always workable here.

Have a read over at the Pat Welsh site, get one of her books at the library, or the Robert Smaus classic, "52 weeks in the CA Garden", and that will give you an excellent basis for gardening very successfully in RSM.

Here is a link that might be useful: pat welsh site on S. CA gardening

Thanks for the info. I am guessing Heliotrope is more of a cool weather plant too. Mine took a beating in this record heat we just had :-( brown, brown, brown...