In cooler climates plumerias will need protection all winter, or as long as freezing temperatures are possible. Plumerias are dormant during this time and can be dug up and stored bare root in a garage or basement, as long as it is dry. They will most likely be defoliated already, but if any leaves remain remove them before moving inside to save yourself from having to pick them up later. They do not require light, food, or water during this time.
To treat an affected tree: With a sterilized cutter, cut below any black or soft mushy area until you get to clean white growth. The cut surface should not show any brown spots. These areas can continue to rot, and travel down the plant and kill it. Treat the cut with a fungicide.
This was the first year I had cold damage. We live near the gulf and don’t usually see temperatures as cold as inland, but this year has been very unusual. The gulf temperatures are lower than usual this year and not providing the usual insulation against cold snaps. For the first time, our outdoor digital thermometer registered below freezing on a few nights. Damage was not limited to plumerias, our Christmas” palms suffered greatly as well. I am looking forward to spring, it can’t get here soon enough.