Your Dahlias will be fine unless you actually get a real frost. I have kept mine blooming until mid October here in NW WI. I did build a big plastic tent over them a couple of nights last year, but I dont think it was needed. It was about 40 here last night and they look very happy. You dont over winter whole plants indoors. Cut them down and store the tubers when you finally loose them to a hard frost. You can search this forum for dividing and storing tuber info.

Thanks! Apologies for incorrectly implying that I'd winter the whole plant indoors- that would be a pain indeed!

Do you think Tenting will produce happier plants (aka more flowers) from now until Oct 8? There are a couple of Cafe au Lait Dahlias that are growing, but have no buds on them yet (I planted late). Do you think the added heat will help?
They are all along the East facing wall of my brick garage.
Thanks again.

Pic of White Dahlia including pin sized holes some bug is making. I've seen rice-size & shaped black bugs and cucumber beetles on the flowers. Have yet to see an earwig in the entire garden (even went out with a flashlight at night).
{{gwi:654742}}

I wouldnt tent unless it is going to freeze. The Pacific NW is Dahlia country, and cool and grey is the norm there. Pretty Dahlia!

Beautiful white! Do you know the name??