I have two brugmansia "angel trumpet" plants that were growing beautifully about a month and a half ago. They were each about 7 feet tall and very leafy. We had a light frost for a few mornings in a row plus the heavy rain our area had all winter. They both turned yellow and all the leaves died so about a month ago, I trimmed them all down thinking that they would recover. My questions are 1) are they dead? I cut the canes pretty far down and some are hollow inside. 2) why did this happen? I dug them up because being the avid gardener, I wanted the space for plants that would produce this summer. I put them both in pots to see if they will recover. Any advice would be greatly appreciated.