Rot, too much water, or cold?

[Hantown]

Hello, I have a photo attached of my cactus. Can anyone tell me if it is sick and needs to be cut? It is yellowing at the base with spots along one side (shown in picture, other area of cactus is spot free) I am not sure what exactly is happening here. It is indoor Minnesota, kept by a window with direct and indirect sunlight throughout the day. It was in a fairly large pot for it's size, commercial cactus soil, no fertilizer and I planted it in August. (It was a cuttling without being potted for near 6 months and survived fine) I have only watered it a tablespoon of water once a month near the base of the plant but I fear the roots may have rot. I pulled it out of it's home this morning to check the rootsand I have it sitting in indirect light on top of my fridge (a slightly warmer surface than my countertops) I am pretty new to this, so advice for next steps is greatly appreciated!

[adetheproducer]

Rot from too much water. Cut it off where the nice green stem is and sit it in a pot of dry grit and wait. It should re-root from the bottom once roots have formed water a little to begin with gradually increasing. I would try a different soil mix with more grit, rocks etc rather than peat or other organic materials. I would avoid premises soil they tend to have a lot of peat and sand which is not great. Here is an example of my soil. Ignore the plant the crushed rocks and grit is not just top soil it's like that all throughout.

[greenknight]

Rot is mushy and brown, it doesn't look rotten. It looks a little dehydrated, actually. I don't think the roots are rotten but it's hard to be sure - wash them clean so you can see them clearly, they should be white if healthy. You want to get rid of that soil anyway, get it all off. If there is rot, cut off anything that's rotten, well clear of any discoloration.

Two main things you did wrong - commercial cactus soil, and a large pot for its size. That soil has too much peat, which holds a lot of water, not enough gritty mineral material for good drainage. See the Cultivation forum for discussion of what to use. You could add 50% grit to that commercial mix and it would be ok, but don't use it as-is.

If you don't see any rot after you've cleaned it off, pot it up in a small pot of gritty mix, one just large enough for the roots it has now. Leave it dry for a week so any root damage can heal, in indirect light. Then give it a good watering, until water comes out the drain hole(s). Let it drain thoroughly, then return it to that warm spot and watch it closely for any sign of rot. After a couple weeks if should be plumping up, and you can return it to the window. If it isn't, dump it out again and check the roots.

[Hantown]

the crushed rocks and grit is not just top soil it's like that all throughout.

That blew my mind a little. Makes so much sense, thank you

[Hantown]

Rot is mushy and brown, it doesn't look rotten. It looks a little dehydrated, actually. I don't think the roots are rotten but it's hard to be sure - wash them clean so you can see them clearly, they should be white if healthy. You want to get rid of that soil anyway, get it all off. If there is rot, cut off anything that's rotten, well clear of any discoloration.

Two main things you did wrong - commercial cactus soil, and a large pot for its size. That soil has too much peat, which holds a lot of water, not enough gritty mineral material for good drainage. See the Cultivation forum for discussion of what to use. You could add 50% grit to that commercial mix and it would be ok, but don't use it as-is.

If you don't see any rot after you've cleaned it off, pot it up in a small pot of gritty mix, one just large enough for the roots it has now. Leave it dry for a week so any root damage can heal, in indirect light. Then give it a good watering, until water comes out the drain hole(s). Let it drain thoroughly, then return it to that warm spot and watch it closely for any sign of rot. After a couple weeks if should be plumping up, and you can return it to the window. If it isn't, dump it out again and check the roots.

This is all so very helpful. I am happy to hear it may not be rot! I will update with pictures once I am able to wash the roots, I think they might be ok! *fingers crossed*

[DesertSun]

Rot from too much water. Cut it off where the nice green stem is and sit it in a pot of dry grit and wait. It should re-root from the bottom once roots have formed water a little to begin with gradually increasing. I would try a different soil mix with more grit, rocks etc rather than peat or other organic materials. I would avoid premises soil they tend to have a lot of peat and sand which is not great. Here is an example of my soil. Ignore the plant the crushed rocks and grit is not just top soil it's like that all throughout.

Hello ade! I'd like to ask you a question about your soil if you don't mind. How often do you water it in the summer, since it can't retain moisture? Won't that be a problem in the higher temperatures?

[adetheproducer]

It has fairly absorbent ingredients including sandstones, mudstones, pumice and a couple of other volcanoce bits and Tesco non clumping cat litter the baked clay type. I don't really pay attention to how often I just water once they are dry right through. I guess weekly or even more often if it's hot. The greenhouse does get quite warm for instance it got up to 40°c today. I took advantage of the sunshine today and gave them all a full soak down early this morning. They looked dry on the surface by midday but the stone will hold water for quite some time so I will leave them for a couple of weeks now.

[adetheproducer]

Ps.

I kinda thought some more on this.

Take a look at this search for images, see how many are growing from pure stones.

https://www.google.co.uk/search?q=cacti ... 60&bih=560

I also took a lot away from the stone eaters issue of xerophilia.

Having done a bit of research I am pretty sure that cacti form symbiotic relationships to lithophagic fungi as well as nitrogen fixing fungi/bacteria at the roots. I have seedlings which look great that have never seen organic soils
The only nitrogen they get is what is dissolved in the rain water I collect.

Obviously that is not to say they should not have organic soils there will be species which it is an essential ingredient and organics also offer water retention but I am a bit of a stone eater cult member so I go with pure mineral everyone. I live in Wales in the UK which is damp cold and wet a lot so water retention is not high up my list of priorities.

[hegar]

Hello Hantown,
correctly watering cacti is an art in my opinion. Some of the growers, who have their plants in pots, actually weigh the pots after a watering and then again, before watering, In order to figure out how much water to use. The rule is to water, when the soil has dried out and then water well, until the water escapes through the drainage holes. Do not ever let the cactus sit in overly moist soil for a longer period of time. Some of these desert plants are rather sensitive to too much water near their roots and will go into root rot, which usually is fatal for the plant. I found, that coarse sand and gravel from the desert arroyos here is a great cactus growing medium, because it does drain rapidly. Cacti roots are able to absorb a lof of water quickly and transport it into their succulent bodies. This is a requirement for survival in the desert.
I am going to place a good number of digital images this evening on CactiGuide under the tab "Cacti Places". These pictures do show you the desert environment, including the mineral soils in which these plants grow.
I have to admit to my everlasting shame, that I have killed more cacti than I want to admit, because the soil was too wet. After each winter a few of my plants will not start their growing cycle, because the plant experienced cold and wet soil, which to some sensitive species is deadly.
If I were to grow cacti in a pot, I would have much more influence on their growing conditions and most likely lose very few plants.

Harald

[Hantown]

Roots are white but this bum is woody and flaky. Should I cut and start over?

[ElieEstephane]

I have seedlings which look great that have never seen organic soils

Ditto.
I start my seedling too in pure grit and they have outgrown the ones with organic soil. In addition, root rot danger is reduced greatly as there can't be too much with a free draining grit medium.

[greenknight]

Woody and flaky isn't rotten, at least. Looks more like it was too dry, most of the roots dried up and died. Some may still be alive, hard to tell looking at a photo. It appears to be starting to grow new roots, though, where I've drawn arrows:

sufferincactus.jpg (64.85 KiB) Viewed 3461 times

No need to cut, except for cutting off any roots that are dead. If still rubbery, they're okay, if they're dried up completely they won't do anything except maybe rot. What I think happened was the water wasn't reaching most of the roots, so the plant just cast them off - it was costing moisture to keep them alive, and it was using up its stored moisture.

I would put it in a small pot of pure grit. If the medium is slightly damp that may help encourage rooting, but it should not be very wet. Don't water until it has grown more roots. Once it has rooted well, you can decide whether to continue growing it in a pure mineral medium or change it to one that contains some organic matter (much less than is in that commercial mix, though).

[hegar]

I am still a bit concerned about two unusual things showing up with your cactus:
1. the yellow base and as if drawn with a ruler, the normal green top.
2. the discolored, round, bleached areas mostly around the areoles.
I do not know, if anyone on this forum could give a comment about these two things. Was the plant by chance not exposed to sunlight or artificial light that reached down toward the base? Some time ago, another forum member was asking about these grey splotches that were present around basically every areole. I do not think, that anybody was able to answer the question of what could have caused this. It almost looks like the epidermis has separated from the stem at those locations.

Harald

[WayneByerly]

let me throw MY two cents in. i've only been doing this for about 9 years, so i'm rather new at this too, so take what I say with a grain of salt.

Unless it is blazing hot, let it dry out COMPLETELY before watering. and then SOAK it!!! cacti are plants too, and they NEED water.

pH is also a factor of considerable value. most desert cacti prefer a more acidic pH ... like around 5.0.

the roots in the last picture look fine. nice and white. i don't know what to say about that yellow bottom. put it in a MUCH grittier mix. all of these are GENERAL suggestions, and many cacti have very SPECIFIC conditions under which they will live or die. I've put two cacti in one bowl and had one die and the other thrive.

do what you can to get a positive genus/species identification, then do the research necessary to find out the SPECIFIC conditions that your cactus wants. depending on the specific conditions that my cacti want, i use anywhere between 80 and 100% inorganic soil.

try to save it without cutting it first. if that don't work, THEN cut it.

good luck, and come back as often as you desire. the people here are ALL friendly, kind, polite, and giving of their time and knowledge. this is THE best forum around.