Zinnia seeds and freezing temperatures?
In years past, I have been able to collect seeds from my zinnias after the flower heads die.  There is a freeze expected tonight and they have not died back yet.  Will the seeds still be viable if they have frozen?  Can I collect the flower heads and let them dry and still be able to use the seeds next spring?
I can't cover them tonight.  They are too tall and cover too big an area.