if you want to risk it and you live in the south then mulch well with straw and peg down some fleece over the top.... but I'd lift any that I really wanted to keep and take cuttings from the shoots in the spring so I had some back up plants

I hope someone can help.  I have dug up my dahlias after they were frosted and they have gone mad.  There are about 20-30 tubers on each plant.  Can some one please advise me the best way to split them...

Any of you particularly in the know about growing dahlias?  2 years ago I bought 2 of the large showy bloom types.  Last year and this they have both behaved the same, grown to about 3-4 feet with one...