Do Not cut off or trim any frost injured plants until the danger of frost and freezing is past. The damaged parts may provide a buffer to the healthy parts of the plants during future cold spells.
If you have already trimmed your plants be sure to protect them in cold weather by covering them or moving them to a warmer area. Also if any plants get damaged from now on be sure to move them out of the sun the next day. Heating up the frozen parts too quickly can further injure the plants.