If the tubers are underground, you shouldn't have to worry at all. If the shoots are above ground, you might want to put a bucket or some insulating fern/evergreen, leaves? something over the delicate foliage to protect them. They should be fine if it isn't a sustained freeze.

DapperDahlia - I noticed on your "my page" you said you are growing plants for college money? How are you doing that? I should do that, to help pay my loans!!

Sarah

I was planing on selling them in cut flower shops with coolers and boquets or puting a sign along the road with something along the lines of cut flowers for sale or cut your own fresh flowers. There are a large number of tourists in my area and i figured that might be a rather large market. :o) i have 3 summers until i would be in college and that is plenty of time to see what works and
what people buy. My main plant is going to be dahlias but i have some zinnias and others too. This should be fun!
Carrie