I think it is normal for them to do that way Deebie. They will just sit there until winter is over. I have never covered mine, and never had a late freeze do them damage.
We would love to see photos of yours peeking through the soil.
This is S. 'Chocolate Drop' peaking up in December. It went through snow, rain, freezing rain, frozen ground, thawing again and freezing again.
This is what it looked like in Feb. with more freezing and thawing
March, with still some freezing and thawing
Finally, no more freezing. Here it is in May
