Your plant is not gone yet! I'm sorry nobody has responded mitragorz, that looks and sounds like stem rot. Get a small saw or a blade, not bypass pruners, to trim it and cut below the soft area, sanitizing before each new cut...keep cutting down until you get a cut that is pure white and possibly bleeding white latex. Time is of the essence bc the rot is advancing down and if left uncut, would likely kill the plant.

Once the cuts have stopped bleeding and are drying out, I'll put saranwrap over it with a rubberband and to keep it in place. This assists in callus formation just like a bottom cut, it also keeps the end covered during a susceptible period. Keep an eye on each end in the next few days/weeks to be sure the rot doesn't continue...if it does, repeat above.

It will be saved when the tips stay firm and begin new branches from leaf nodes near the tips cut. You can seal the cut end with your choice of sealant.

Good luck!

-stephen

Did you water the plant at all over winter? If you overwatered, it could have severe root damage. If you did not water it AT ALL, it could be severely dehydrated.

Hard to tell the difference sometimes. But dehydration can sometimes be rectified by gingerly watering around the perimeter of the pot. I usually water my plumerias in the winter - Just a bit, to keep the soil from becoming bone-dry, but not too much to cause rot. Indoors in a warm environment (72 degrees F), one can often water a bit more. If a cold room (50s), very little water.

What was the temp in the room?

It doesn't look too hopeful though.

I only watered them twice so far since bringing them indoors. About a pint-glass full of water each, each time. The room is kept in the mid-60s, high 50s when we're at work.

I started trimming the bad tree, but it was a lost cause. It seemed rotten all the way down to the roots. No white at all, just a sickly brown:

The other plant, I think I'll be able to save. On one stem, I was able to get a nice white center. The other stem, I was able to get a whitish-brown. Is it white enough? Should I go further?

Another pic of the "browner" stem. Should I take it all the way down to the joint?

On one stem, the rot was only in the middle, so I was able to save the top of the plant. I stuck it into the pot of the un-saveable plant. Will it build roots and grow?

Great job on cutting, it's definitely rotting....but cut further, that brown will keep spreading downward....sorry you lost one....cut til no brown at all. Be sure to sanitize in between cuts...I even drip a little h2o2 on the cut wound once I get to all white flesh. I cut in just a few inch sections to save as much viable tissue as possible.

You might need to take it down to the joint...if it's still brown down near soil line, it may be too late. How are those other tips? You may be able to cut those and re root them to save them.

Sorry this happened, but you might be able to save some of it. What kind was it?

-stephen

Nice color! Alcohol is fine to sanitize too...Yes I'd take the whiter stem down a little bit more, the right side looks too brown...it shouldn't have any of that at all. Watch the other tips for any softening on either end. The soil looks pretty wet from the pics, maybe look into amending for faster drainage if it stays wet too long.

Good luck!

I had just put some water in them. The soil was so loose and dry that the plants were wobbling around.

After cutting more and finding the inside becoming browner again, this is what I'm left with so far. Think it's also a goner?

Yes it looks like it...the rot has gotten to it. What a bummer!

-stephen

I'm so sorry to see this..

Laura

I think you'll have to start over with a new plant. But the question remains .. what caused it? Really, plumeria should winter over just fine in the home. I'm wintering some over in my cool garage and it got a little too cold in there for some. They are getting black tip.

But yours likely got too hot, dry, dessicated being too close to a heat source without much additional water. Not sure.

I've had a few - 4 to be exact - of mine to do this this winter as well so you are not alone. Mine were fine during the summer and for some strange reason they decided to take a nose dive and kick the bucket on me all out of the blue.

Yeah, it's a bummer for sure. I really think it was from being right next to the heater and not being watered enough. They survived six winters in NY, I feel bad for not giving them enough attention.

I think I was able to salvage a 4 or 5-inch tip. I stuck it in the soil, maybe it will root.