Please post a picture so that we can see the size of the container and the type of mix. That will determine whether a re-potting will help.

Josh

Well, the damage has been done, so please don't fret yourself into a sleepless night. I have burned them, froze them and generally made myself a target of the plant police. They can be tough. If you get it back to the place where they thrived before, it could conceivably re-start. Keep it warm and moist, but not wet. Do not trim it anymore, let the pieces wither and shrivel.

Do not re-pot or otherwise disturb it any more. Remember that with less greenery, it will need less water. And wait. This is not the time of year it makes new stems, so if it just sits there, that is normal. The parts nearest the soil need to be somewhat succulent for re-growth to occur. The brown bark nearest the soil covers the green that photosynthesizes. If you have even 1/2 inch of sturdy stem, you will probably have a little plant in the spring.

Here's one pic.

Here's another, and you can tell from the other cactus in background (which is much younger) that I can keep them alive.

It looks like you have plenty of plant for it to grow back. My caution would be not to over water it. If it gets too much water, it will turn wrinkly, and this may look like it is drying up, but it is actually the opposite problem.

These plants are very easy to propagate. I have a lot of epiphyllum (not yours, however), and they grow like weeds for me. My Queen of the Night is now so prolific that I have cuttings in six or seven pots. I think it would probably grow inside, but I only bring it is when it is about to bloom.

If you need another plant, you could probably find someone to send you a cutting. Mine are all outdoor plants, although they would probably grow indoors with enough light. My problem (like what happened to yours) is providing them with enough shade.

I think that with time yours will recover.

Lars

Definitely re-pot!

Move it into a smaller container, otherwise that volume of soil (which might have been fine for the full plant) will hold too much moisture and could rot the roots as the plant attempts to recover.

Downsize as soon as possible.

Josh

Wrong soil, wrong size container, for a start. I agree with Josh. If you want to save the plant, repot it. In that large a plastic pot, it may not survive if you wait too long, in my opinion.

Christopher.

By the way, I am surprised Josh has not already mentioned that it appears to be a Thanksgiving Cactus, not a true Christmas Cactus.

Christopher

The reason to NOT re-pot is that the top has been damaged. Why would you compound the stress, and damage the roots? There is no way to re-pot one of these with their tiny fibrous roots without tearing some. Torn roots are another way for pathogens to enter the vascular system. Careful watering until the plant gets on its feet is still my recommendation.

Christopher, you are so right! Ha! I must be slipping ;-)
In its haggard state, I didn't even notice the leaves. Yes, this is a Thanksgiving Cactus.

The stress of a large volume of water-retentive mix is a far greater stress than a few torn roots. This is the not the best time to re-pot, certainly, but it should be done in order to give this plant the best chance of surviving.

Josh

I still have to agree with Josh. This is an emergency measure.

Christopher