The first does not look like sunburn, that would be light brown. I have seen the same thing on two of my cacti, and in both cases it spread and the plant died. You could mark the border of the dark area with i felt-tipped pen, wait for a few days and see if it spreads. If so, get rid of it.

The "moon cactus" is doomed.

It looks like rot to me.

My questions are:
- Why do they look like they're in HUGE pots? My cacti look to be the same size as yours, perhaps slightly bigger and their pots are only 2-4inches. Too big of a pot could be leading to the rot.

- In my opinion (and if I've read correctly on here)rocks on top of the soil is a huge no-no unless they're only there for a couple of days because you're showing your plants. Otherwise they hold in too much moisture, therefore, also leading to rot.

For the saguaro, you could try cutting off the black part on top, potting it into a much smaller pot (only and inch or so larger than the root ball) and removing the rocks. Don't water it for a little while and see how it goes.

The moon cactus seems to have a teensy bit of green above the black. You could try cutting it off there and rooting it, letting the cut callouse over for a few days before putting in soil. But that I'm really iffy on.

Good luck. I hope everything works out for you. And if a cactus seems dry, don't worry about it. They're used to it. Err on the side of dry.

Yes, like bunnygurl alluded to, they are in huge pots that inevitably remain moist and lead to rot.

The saguaro appears to have rot at the growth point. The prognosis is very poor, unfortunately.

x

I woke up this afternoon and the moon cactus is completely toppled over on his side. There is a very little bit of green left so I am going to cut him off and let him callous over and see if anything happens. I have nothing to lose with him.

On the saguaro I noticed the black a week ago and it does not seem to have spread. I have marked it and will see in a few days. Friday morning I will head up to a garden store and pick up smaller pots and cactus soil for a Friday night re-potting. I am very apprehensive about cutting into him as I have no surgery experience so I am going wait to see that it is spreading. I will pick myself up an x-acto knife and be prepared in the event that it needs to be done as a last resort.

Is there anything I can watch out for to tell if it is rot on the saguaro, besides the black are there any more symptoms? In the event that surgery is necessary any tips for cutting?

Thank you for the help so far.

J

I didn't notice the rot at the bottom of the saguaro. If it is rot, it'll look like the moon cactus with that whitish color coming in over the black. It'll be mushy, and yes, inevitably topple over because the mushy stem isn't able to hold the rest of the plant.

Another way I think you can tell is to take the plant out of the pot and smell the roots. If it smells mouldy than it's definitely rotting. I'm not sure on this as this is for regular plants, but I'd assume it'd be similar.

When cutting, cut above the black (not sure how this'll work seeing as how the saguaro has black on top too, but hopefully that's benign) in a straight line. The cutting should be clean, green and plump. If there's any black on the inside of the cutting, then it's too late. The rot as already spread throughout the plant. You could try cutting farther up to see if there's a spot where there's no black, but you need some substance of the cactus left to root. Let the wound heal outside of soil for 3-7 days. The larger the cut surface, the longer the drying time.

Pot it up in a very well draining mix when it's healed and don't water right away. Wait a couple days then water thoroughly, but sparingly. I'm not sure how long it takes to root a cutting, but if all goes well, your cactus will be saved.

I'm not sure if you put it in sun right away or not. I think probably indirect light until it's rooted then gradually increase to bright light, but any clarification on that would be great. I'd like to know as well.

Oh and I forgot to mention earlier about the roommate never touching your plants. I agree on that unless they know what they're doing. My hubby would lose his hands if he ever even attempted to touch a leaf on my plants. Hehe.

Good luck.

Unrooted cacti should be placed out of direct sunlight until they can take up water again.

Top-dressing (the pebbles on top of the soil) is not necessarily bad, it depends on the soil and growing conditions. I use it on almost all my plants, including some that do not like wet soil.

On the bottom of the saguaro (the first two pics) that's not rot, or if it is it's how he has been since I purchased him 2 and a half months ago. I figured it was a stem or trunk of some sorts, that was between the roots and the spinney green part. It's a tan brown and it pulls in tight so there is some heavy shadow and some clumps of the potting soil that he came in.
About the rocks, I read a couple places that the rocks will help keep the plant warm during colder temperatures and I thought it looked nice. But will definitely re-pot him tomorrow night without rocks. I'll go with a smaller pot and cactus soil.
On the moon, I cut all the brown and was left with about a half inch of the green stem. I doubt it will root but I have nothing to lose and possibly something to gain by trying.
Thank you to everyone so far.

J

It is possible that it will root, Hylocereus root easily (if there are no traces of brown left in the remaining part), but it might not have enough green tissue left to do the photosynthesis for the grafted plant.

an update and another request for help.

I have placed the inch of moon cactus in a coffee cup with some soil. I made an effort to make as much of his green skin open to sunlight. Here's hoping.

After reading a thorough webpage on rot I opted to operate this evening. The surgery just finished. I apologized during the whole event which took about 15 minutes. I started by trying to be conservative and after seeing dark spots inside, opted for more "drastic" cuts. I have removed most of his black parts. Now I am looking for aftercare. Is there anything I can do to help this heal over? To help prevent against infections? And my last concern, after every cut his insides were like that of an apple. He was very wet inside and he has started to "brown" like an apple after its insides are exposed to air. Is this normal or should I be worried?

I have a couple pictures of the post surgery if anyone would like to see them.

Thanx again for all the help.

J

PS: He also has a new pot that is ultra-conservative.

My question is, this coffee cut you have the moon cactus in...is it a real coffee cut of a pot in the shape of a coffee cup? If it's a real coffee cup, chance are good it doesn't have drainage holes, right? If so, this just help the rot along even farther.

The cut should callouse over on its own over time. I've never heard of a cactus cut getting an infection. He's wet inside because cacti store water, so that was probably just his water storage.

It would be good to post the pictures of the cuts so we can see what you mean by the 'apple effect'. Also, I'd like to see the pots you put them in, if that's alright.

I'm really hoping these guess keep going for you. You seem to really love them. Good luck.

As requested here are some postop pics.

The moon is too fargone, I have given up on him. :(

{{gwi:540892}}
This is minutes after surgery. Notice how in the center it is starting to brown, like an apple. That's what I mean when I said "apple effect". He was completely clear after surgery.

{{gwi:540893}}
This was taken this morning, 18 hrs after surgery. Notice how its starting to brown again. It has me a little distressed. Am wondering if this is like a "scabbing over" feature or more rot setting in. I have also noticed that the moist inside has pulled back into the skin around the edges.

{{gwi:540894}}
And finally his new pot. Here you can also see how much I had to cut off.

I have already decided that if he doesn't make it I AM getting another cactus. I am just sad that this one had to maybe pay for my learning experience with its life. I'm a big softy when it comes to ANYTHING living.

J

Hi, I hope that's not a self watering pot. The style of the bottom of the pot reminds me of one.

For the future, when you get the NEXT cactus, they do better in clay pots which help safeguard against possible overwatering. Good luck w/ it.

The pot at least looks to be a much better size. I don't see anything unsual about the cut. This is most likely it just healing.

If it doesn't survive I do suggest getting another cactus. I love my cacti and it took a couple tries for me to get the hang of them. And if you do, definitely follow PGs advice. And err on the side of dry unless it's shriveling...then it's too dry.

Good luck.

Another trick is to use cinnamon on fresh cuts to help prevent rot.
I know it works on other succulents, particularly when root-pruning...
I don't know about top-cuts on cacti, though.

Good luck! Update us on your project.

Josh

If you love your Saguaro - neglect it!

I would not put the Saguaro outside in Florida, unless it was protected from rain and humidity and had plenty of drainage.

You said 'it looked dry so I watered it a week early' so what, when it doubt, don't.

Find a southern exposure window, leave it there, place in a terra cotta pot, appropriate for it's size - (diameter should be 1/2 the height of the plant).

I wouldn't keep moving it either - let it alone and let it get adapted to its space. Water once a month or less in the winter (depending how cold it gets) and twice a month in the summer (April to October). If you give it good drainage and a good spot the admire it, but ignore it and it will live for years and years.

Not a fan of the Moon cactus - Frankenplants if you ask me...

Sagebrush

Hello! I am so sad! I had a Saguaro named Tucson like the one pictured above since 1997. He was as tall as my thumb and grew to be 7 inches tall in the last 12 years. He was repotted a few years ago and has been thriving on the schedule I had him on (watering). I just watered him the other day and today I went in and saw that he had deflated at the bottom, and tipped over, and broke in half!!!! There was no black or anything. Just dark green plant material exposed..very mushy...and his color changed from the bright green to a dull swampy color and light brown in some spots. I am so devastated!! What did I do wrong? Was it the water?? I know he probably can't be saved, but if I can avoid this in the future, it would mean a lot. Does anyone have any advice?

Thanks so much,
Donna

Could be the watering (most likely). Could be root damage caused by an insect + an infection. Or just bad luck. All growers lose a plant now and then, but the losses are smaller for the experienced ones.

I have a 4 foot tall healthy, thriving Saguaro, and I live in chicagoland..
It stays in the house in a southern exposure from October until June.
It gets watered MAYBE 4 times during those EIGHT months!
Once it goes outside, I water it about every 2-3 weeks in the summer, using a moisture meter as my guide. Plus, you must ALWAYS have the same side facing south, or they will burn and die..I mark my pot with a painted red dot, so I know to ALWAYS keep that side facing south..VERY IMPORTANT to NOT turn these guys..

You MUST keep these guys super dry in the fall/winter, and even in the summer, they can go awhile without water, even if its 90-100 degrees. They are like sponges; you can see them swell up when you water them, and you watch them start to shrivel up a bit the dryer they get.
Remember, they are native to the Arizona desert, where they might get 4 inches of rain ALL YEAR..Overwatering will kill these guys, and that is what you did to your little guy..My 4 foot tall guy is in a 14 inch diameter pot, which is only a little bigger than they one you had your little fingerling in.

This is going to sound really stupid, and I think I am just in denial...but is there any way I can save him? He completely broke in half and the bottom half is mushy and open at the top :(.
After 12 years, it's really hard to let him go. I have him under a sun light to dry out. What if I re-pot him in dry soil? Do they ever come back from something like this?

Forget it -- I don't wish to be mean or cruel, but in succulents, mushy = rot = death. Throw the whole thing out, since it's the bottom you said is mushy (rather than the top). It's a goner -- sorry, but that's the truth. There is no bringing it back, tho' it costs nothing except your frustration & raising false hopes to try.

Wase4711 I vote for your response, you are right on, and you plant seems to love what you are doing for it. Pirate_girl is also giving you great advise, it is a grafted plant, and it's host has died from too much water, to keep these alive it takes a very keen grower, so don't feel bad, this is not your fault, it happens to these plants all the time, 'Moon Plants' are artifically done. Try planting native desert plants in pure pumice, and follow the rules of nature for success. Crasulady2 who also grows catus.

next time something like this happens try to Graft it. look up how to graft it.