Not very much. Keep your fingers crossed. Depends on a lot of micro-climate issues whether they made it. When you say it got down below freezing in your area, is that in your yard, or just what the weatherfolk said? I am close to downtown and my yard is always a couple degrees warmer than what they read at the airport out a half hour drive from the city. Even on your property, there will be warmer and cooler spots, depending on shade, slope of the land, etc. But if they got frozen, they are gone.