Sadly, you are going have to cut all of the dark squishy hollow stuff back until you hit firm wood with a white center. Does the damage go all the way down to the base of the trunk?? If not, it will branch out from where you had to cut to, but you will probably not get any flowers this summer because it will need to grow out a bit before flowering again.

If the damage is all the way down, then it's a goner.

Good luck and keep us posted,
Tony

Cut it all the way down until you get back to a solid trunk. It wont flower, but it should at least get some leaves back and some good growth and possibly bloom next summer.

Good luck!

In addition to the excellent advice above I would just add to not be too quick to declare it lost if the damage runs to the base of the plant. Two years ago I thought I had lost all my in-ground plants to a freeze. When I started to dig them up, I noticed the roots looked healthy. One even had new growth at the base of the plant. ALL the plants were alive and sprouted new growth at the base. I did dig them up and put them in pots so that I could care for them as they recovered.
Mike

Thanks for all the advice, I ended up having to cut it down to the trunk it was completely black and rotten in the center and smelled really bad. The trunk was only slightly better with an off-white center but solid trunk and not squishy at least. Sprayed it down with a fungicide and painted the ends with tree sealer, now I'll cross my fingers and hope it makes it.

I also had a number of large plants in one of my hedges that froze in 07 and several have come back so hang in there.

Wow, I'm amazed but almost two months later and guess what this little guy ain't done! I just noticed a new sprout coming out of the ground right at the base of one of the chopped down trunks. I'll take a picture of it tomorrow but I'm really glad this little guy didn't kick the bucket after all.

Glad to hear the freeze didnt kill it! Post some pics when you get the chance!

Good luck!
-Alex

I originally only saw one but looks like two on this stump and the other stump has a tiny bud coming out, took a pic but it came out fuzzy I'll wait until it shows some progress before I snap another pic. Thanks for the help folks it literally saved our Plumeria!

That looks like a really promising come back! Your plumeria might take a while to get back its height, but at least now it will be fuller at a smaller height!
Good luck!

watch the main stem to note if it is rotting down from the top. I cut mine and coated it with DAP Alex plus tub and tile sealant. It has been good for several years and the new branches are a yard long now. It will be back. good luck

Well it's been a couple of years and one winter where I had to build a shelter for the plumeria, basically built a cage around the entire plant with 1x4 treated wood and covered it in clear plastic. I also added a makeshift heater, basically took a simple work light with a 60watt light bulb with an 8inch reflector and clamped it to a brick facing into the center of the canopy but away from anything flammable. I set it up on an outdoor timer to run from 11pm to 8am when it was the coldest, I placed an indoor/outdoor thermometer to monitor the temp inside the shelter and on our coldest day it was 15 degrees outside but inside stayed a comfortable 65 degrees. Everything else in the area froze except our plumeria, I'm sure everyone that passed by and saw this huge tent must have said I was crazy but I'm sure they were wishing they had gone the extra step to save their plants! Thanks to everyone for the help and suggestions we're happy this little guy is doing good and we just wish we could take it with us when/if we decide to move.

Beautiful, Albert! What a testament to your care that the tree looks like it never suffered a thing. Thanks for letting us know how it's doing!

Some of us are at the coast and keep trees in the ground year-round; I'm sure they'll be interested to hear that they will come back from a hard freeze with the right care, and after only a couple years, too.