I always heard no plastic.If you dont get it off right away and sun comes out.I hearsd burlap,Ive used bigger pots,boxes,you can also pull milch up around them if theyre smaller.,sheets,

White cotton sheets are the best. Once the sheet gets wet, its effectiveness gets compromised. All attemps should be made to dry it out after the rain stops before using it again.

White plastic can be used if it is removed and dried out each day. Never use clear or black plastic. That is what you use to make a solar oven and kill everything.

I had my plastic all set up to go tonight. I had an inkling it wasn't a good idea, but after reading your comments, I just covered everything with pots and empty window boxes. Should I uncover them during the days when it is in the mid-high thirties or just let them covered? It is supposed to get warmer again starting Monday. Thanks for any additional advice! I appreciate it!

Uncover during the day.It is alot of work but if you want the flowers......