That looks like a Euphorbia and in my experience Euphorbias can take forever to root! I had one that took 6 months. I cut it in Feb. because of rot. Did not see roots till August.

From what I can see the bottom two thirds don't look too healthy. Some parts look rotten. If this were mine I would cut right above the yellowing, and if the flesh is good. Just wait and be patient. Let it callus. Then put in some mix, keep warm, no water, in a filtered bright lit area, and forget about him:).

Generally cactus are quicker than Euphorbia. I would say the quickest I've seen cactus root was around 2weeks. It was an Opuntia. Have a Trichocereus that rooted about that fast too, maybe more like 3 weeks. Definitely under a month.Other cactus take a month to about 4 months. Just depends. But Euphorbia cuttings will test your patience;).

It can vary wildly. I have learned to never give up. It may take a long long time and then surprise you..

@kara, I did cut all of these up until only green was showing. As I said, some proportion of them then rot. To make sure they did not suffer in wet soil I leave them on their sides on top of gritty mix. How important is it for the base to be planted?

So I absolutely must keep these out of rain until they root? The recommendation is to leave them lightly placed into gritty mix for up to six months, totally dry and unwatered for six months?

westes

I believe your response was to Kara :)

But I do agree with her suggestion to cut until healthy flesh remains. Many succulents will root without being buried in the soil. I would also keep them dry until I see some roots developing, or if you decide to stick it into mix - when plant feels established in it; and that may take few months.

I know it sounds crazy but keep it dry, warm, and in a spot with filtered light. Could take as long as 6 months, could be sooner. The ones that took 6 months honestly didn't look too bad. Even for that long without roots.

You keep it out in the wet cold winter, the possibility of rot is huge. Euphorbias are so sensitive to the cold.

Sometimes rot progresses further up when the area we cut has some infected tissue still. Other times if we start lower the stem and cut upwards, the bacteria jumps onto the upper part of the cut from contaminated tools. Disinfect the cutting tool each time and cut well above any yellowing. As suggested by the others, best to cut well above the yellowed part - disinfect the tool with a thorough soapy washing/alcohol first. If the cactus survives it will grow and get its height back!

I find succulent plants are encouraged to root when I lightly mist the base after it has calloused - just 1/2 shots occasionally then let it dry. Maybe a very low amount of humidity tells it that it's time to send out roots. I've seen people root succulents in water with good results, then transplant them into soil. And cacti are a kind of succulent plant :)

Given that each cutting completely covers the tool with a sticky - and nearly impossible to clean - white latex sap, I am not sure how I could possibly "disinfect" the tool between each cutting.

@rina, I will try bleach but I have had no luck in anything cleaning off that horrible sap. I end up putting on packing tape above the cutting edge and literally peeling it off the main part of the blade after I am done. That works great, but it is a one-time operation to put it on and take it off. I'm very skeptical I could ever clean the sap off cuttings. But maybe it is enough to kill the surface bacteria/fungus....

To update this thread, I tried cutting back the remaining Euphorbia. The smaller ones simply shrivel up, almost like petrified wood. The one substantial sized Euphorbia appears to have died near the base, and the remaining part of the plant is starting to wrinkle and looks water-stressed.

Looking at the following photo, how concerned should I be about the die-back at the base? Is this plant likely to root in a few months? I have it planted in dry sand+turface. I am not watering it. The base was smothered in rooting hormone powder while still wet. It was cut about two months ago.

How much of the bad area did you cut off?

If this were mine I would have cut here.

The bottom area just looks bad and not a good place to start for a cutting. You want as much healthy Euphorbia as possible. Leaving anything on the right side of that yellow line I wouldn't think roots would come out of that dry unhealthy growth. That's just a guess. The left side looks like a much nicer spot to try to get roots out of.

Lastly, remember when I said my Euphorbia took 6 months to root. Well that means I left it alone and did not lift and check for roots. You have to leave them be during this slow process. If this was personally mine. I would cut off all the bad areas like I said above. Let callus for a few days. Then set on top of some mix and just leave alone. Don't go checking for roots once a month or every other month because they probably won't be there. Plus not the best time to be doing this because it is winter. You will know when roots have formed. The plant will start getting new growth and just look better.

The ones that took 6 months to root are finally pretty well rooted into their mix. It took them 11 months to get like that.

@Kara I followed your original instructions and I cut about one inch above the yellowing area. It was a clean cut and what was left looked healthy. I'm just reporting back with the new photo that shows that the area that was cut died off. But the die-off is a very thin layer. It doesn't look like root rot. I'm not sure what it is.

Could you take a pic of the whole thing? Are there any plump green areas?

It's only been two months and it's winter. So yours could take a long time. The Euphorbias that took 6 months to root I cut in Feb 2017 so Spring was just around the corner. You've gotta be patient with this one. If it keeps drying out. You could trying rooting in water, but I've never done that. I've read people doing this with certain plants. Even with Euphorbias. I can give zero advice in that department though.

The first Euphorbia I bought was a Firestick. I has rooted other succulents with no issues and they would root in a fairly responsible time. For the longest time I did not think Firestick cuttings rooted because they took so long, but eventually they did. I just had to ignore them.

@Kara, I was not asking about the lack of rooting. I was asking about the necrosis where the roots might have grown at the base of the plant. It's clearly black and dead tissue there. Full photo is below. It looks like it has yellowed a little since the cutting and I see water stress.

This pic doesn't look too bad. Just put it back and leave alone.

The little yellow marks are were roots are likely to come out. That area still looks firm and not dead. Just be patient. No more disturbing.