I would cut off a few of the tops with good growth and plant them. Cut it like in the photo. Just do one section. Put the cutting in a dark place and allow to callus. Once the wound is dry stick it in sandy soil. That will give you a new plant. I think the mother plant will be ok if you slowly give it more and more light. Avoid direct midday sun for three weeks. Looks like a dragon fruit plant. If it is never give it full midday sun if you want it to fruit. Morning and afternoon sun are ok.

Looks more like a euphorbia to me but can't tell more from the pics. You'll know if there's white latex when you cut (careful with this). In any case, that's some good advice :)

-Ming

I believe Ming is right, this is a Euphorbia. If it bleeds white latex, that is the proof. But beware of the latex, it can cause skin and eye irritation, so take precautions.

I would take the plant out of the pot and check the roots for rot. Also repot in a fast draining potting medium, I would use a clay pot. If the plants roots are good, I would wait about a week after repotting, and then water thoroughly. Cuttings can be taken for rooting separately.

Christopher

Thanks for all the advice everyone, I appreciate it! I think it might be a Euphorbia after looking at some photos online, too. I guess I'll find out when I cut the tops off, which, by the way, thank you for the warning about the latex (juice?).

First thing I did when I got it today was water it since it hadn't been watered in months. I now realize this was probably a mistake. I may be able to wrestle it out of the pot tomorrow to check the roots and re-pot dry in a fast-draining potting mix. What signs of rot/healthiness should I be looking for?

Any tips for how to take this out and re-pot it? Can't say I've ever wrestled with a 5 foot spiny plant before and some of the main arms are weak/soft.

Speaking of, should I cut off any smaller arms that are black/collapsed? And can I do anything about the mold spots? Or does it all depend on the condition of the roots?

P.S. This is the photo that was used to advertise the plant, taken probably 2 months ago before the tenants of the place moved out and left it in an unheated basement. In Michigan (during winter).

And here's what a lot of it looks like now. Collapsed arms with green tops. Main stems are dark/dull with brown scabbing and mold/fungi (see black spot in the bottom left).

A large pot of Euphorbia trigona is always on sale at Lowe's for like $20 here... It's going to take a lot of effort to rescue that thing. I'd cut the tops off for propagation, junk the rest and call it a day. You could reuse the pot, though!

-Ming

Milky white in color sap that flows slow Mist with water to slow the flow down AVOID contact to skin eyes and open sores. Bleach & water mix to clean all tools after
If rash does develope may need medical attention

Any black or dead areas need to be removed. Cut back to pure green growth. I would take stem cuttings too, but I would still try to save the main plant, if there is enough left after removing the dead portions. This is not E. trigona for sure, but there are a few similar Euphorbia to this, making a positive ID difficult.

Good luck with it, I wish you success.

Christopher

Hey Fish,

As Ming has suggested, you may be able to purchase a new juicy plant locally for a very reasonable price.

But as Christopher has suggested, and you are up for the challenge, I would also try to save it.

When it comes time for me to repot one of my larger plant's (trees in my case), I find it much easier to suspend/ hoist the plant off the ground a couple of feet. So in effect, you are removing the pot from the plant, not the plant from the pot.

So, in your case, a bed sheet wrapped and tied around one, or multiple stems, and hung over a tree branch, (or whatever works), may make the process much easier for you.

Good luck

Dan

Some Euphorbia should not be watered at all during the winter or when they are dormant. So you might want to stop watering it right away. Also if you moved it from a basement to a new location it would need to adjust to that new location before you started watering it.

Furthermore if it was in the dark and you moved it into the light you can damage it as well. It's usually suggested you do this slowly (aka physically moving it towards a window over a period of days) as to not shock it.

I agree that you need to assess what is actually rotten and separate it from what isn't rotten. Hopefully you can at least save the base of the plant.

Otherwise you will have to leave the green living tips to dry for a week or two and then put it in soil and allow it to grow roots in a smaller pot. It will eventually root and you can move it to bigger pots and it will grow fast given enough sun and light.

First, thank you again for all the responses! You have all been a great help.

I took cuttings from the healthy tops and have them drying in a dark closet right now. I'll try to start rooting them in a week. Some are only a few inches tall but hopefully they'll still root?

I'm sad to say that the base of the plant isn't going to make it... it was just too far gone and was rotted through to the bottom. It was definitely some sort of Euphorbia with white latex and I'm hoping to be able to find something similar at our local Lowe's. I'm just hoping now this wasn't a 10 year old plant or anything, haha.

I didn't know that some plants could be damaged/shocked by sudden changes in lighting conditions, thanks for teaching me that! :) I think the cold and poor circulation before I got it is what did this poor plant in, but I'll remember that for future plants.