Tyler,

I appreciate the response! They have definitely shrunk.

I have had these plants for a little over a year and both put on some pretty good growth this past summer (the vulcanorum about doubled in height). They were outside from end March till late October receiving full morning sun for about 6-7 hour period and shaded sun from late afternoon on. I do not have any close up photos of these plants individually, but I do have a photo below of the set up when I started them in the garage in late October.

It may be hard to see in this photo, but you should be able to see how the bottom has shrunk from then compared to now. I really have only watered about once every 4-6 weeks during this dormant cycle, from what I have read is suggested.

Take a look and let me know what you think!

-Josh

Let me start off by saying I am green with envy. I have been eyeing Euphorbia vulcanorum for some time now and it is a gorgeous Euphorbia. The flowers are incredible. They're small but pack a punch along with the way they perfectly uniformly line up, just the way some Euphorbias know how to do;).

Sadly, I think it may be time to dig this thing up. See what's going on to better assess what should be done. Another thing Euphorbias know how to do really well is to get rot, but then the rot turns to dryness that just spreads all the way up. I wouldn't chop until you check out the roots.

It could be that it's put on a ton of growth and this completely normal. Tbh tho that has just happened wayyy too quickly. I would cut open a little side growth and check it out first.

What are the temps at night like in the garage?

To me, some of that base looks dead: hard and woody, completely desiccated. Looks kind of like what my whole plant looked like after it got left outside for too long this fall. RIP my plants.

This is just my opinion though and I hope there's better news to be had for you from somewhere else.

Ya I agree Laticauda does totally look desiccated.

This is a tough one;). I don't like how quickly the bad part has taken over. I was reading these are only ideal for zones 10 and up. Of course that means if the plants are outside, but I wonder if your garage dropped in temps a few times. Doesn't take much or long. I feel for you Josh the plant is beautiful and your stuck between a rock and a hard place. I probably would chop, but I'm not afraid to chop. I'm not saying you are afraid, but it can be a scary thing. Especially with such lovely plants;). Now would be a good time to chop if you do.

Just wait and sleep on it. Maybe somebody else will chime in. How about taking off that little side piece and inspecting that;).

I agree with Kara and Laticauda. The roots look ok in the picture but I would inspect them closely to see if they are actually solid inside. The bottom stem does look like it has died back. Kara may be right about rot. I have had Euphs' stem ends dry like this. Euph. grandicornis does this every few winters because it doesn't like it too cold. The burn from the top can just be cut away. I'm not sure what to do at the bottom. I'm not there to see with my own eyes but if the pictures tell the real story it is time to cut at a clean spot. Dip the cut end in water to stop the latex. Let it callous. Put it in a pumice or perlite mix that has been cooked in the microwave to try to sterilize it. You'll have to have a lot of patience. If all goes well you may have roots again by summer. I hope you can save them as you have some very uncommon Euphs. there.

If it were mine, I'd chop and let it dry/callous inside the house, where it's warm(er). No pot or pumice needed. Just lay them down and wait for spring/summer. (This is what a cacti&succulent business owner does with propagates all the time.)

When I said "maybe somebody else will chime in." I was hoping it was Aloebot:).

While scrolling this thread and reviewing the photos again. I believe they got cold damage from being on the floor. The floor is much colder than the ambient room temperature, I'm thankful it didn't get the whole plant.

in my opinion, it's not rot but the plant using old resources to sustain the new growth since it can't take anything up through the roots. Just my 2c

edit: kinda makes you feel like a CSI, donnit?

Re-edit: my phone autocorrect makes me look like I don't know English. I also realize this makes it more difficult for non-native English speakers to understand what I'm saying. It gives me fits.

Euphorbias get this weird dry "rot" that I've never seen on other plants.

When I put plants in the garage on the floor I always wonder if the cold concrete causes problems.

I didn't even think of the concrete, I was more referring to the draft of cold air that flows across the floor. Don't you think the concrete would be a "heat sink" from the warmth of the earth?