I cover my trees with 4 mil plastic over pvc pipe frames/domes, and have small desk-size space heaters plugged into thermocubes so heat comes on at 35 degrees and turns off at 45 degrees. I uncover or vent trees when daytime highs in 50's to try to keep trees dormant. Also have 32 gallon water barrel under cover with each tree. I'm trying to load a photo but power is out here right now, so have no wifi and bad cell signal on this mountain.