Tonight I am mulching and moveing plants around, hopefully for the last time. Talk about crazy weather, it was 80 last week, Today there are scattered flakes falling. It does not feel like it is 30 out, I think it is something like hail, some sort of convection current, I have never seen it snow and thunder and lightning at the same time. Redbud, If it dips below freezing for very long your plants will be damaged. If you can't move them inside cover them with at least a double layer of burlap or a tarp.
Old blankets work great also.
The key is to keep the cover as close to the ground as possible to trap the natural heat from the ground. We're going through the same thing here in Ohio, fortuneately we haven't had as much warm weather, so many plants are resting peacfully. The maples around my house were not damaged at all and nothing really happened. The ground cover plants and cannas can be covered to help prevent frost bite. I think that as long as the temperatures do not stay below freezing for too long you will be safe.