That's disgusting and disappointing!This has happened to mine before but it did fine with peroxide to the rot and sealed it with wood ash.
This might work for yours but that one will die or continue to rot unless you cure it before repotting.

Ferocactus are very tough,they can even take on snow.

They have grown fast in the last two weeks from just a few spots into this so I had no idea what is happening.
It is a nice cactus and I didn't want to loose it! I am hoping for the best!

I like the look,success!

Now with these photos it seems to show the terrible brown spots pretty clear.

GEDC0198.JPG I don't know what is causing these brown spots in the skin of this cactus.So I decided to cut a section of skin to see if I could see any sign of necrosis but no it was very healthy looking. what could be the cause of this low light conditions, I am not sure.Anyone ever had this before...

Maybe there is a large worm hiding on some of your cacti,they can do quite a bit of damage.
I have caught one in my cacti eating away!

I hope that you are still making progress with farming and your greenhouse.The space where you are making your cuttings is such a really great idea!

It maybe 93F but the temps in the greenhouse could be 120F but the humidity is very high which may make it feel hotter. There are many different types of cacti growing in there some are flowering. I want the best environment I can provide for them,which has been lately very high humidity and high te...

I did notice the soil cooking!I had never seen anything like that before!
I will work on some ventilation and add a thermometer because vinyl does get hot.
They have never had any signs cooking or dying due to high heat.

Hey listen I have a vinyl greenhouse that is full of cacti. Lately the temps are getting pretty high and when the door is opened it you know it is getting hot.I can touch the soil on larger cacti and it's like it is cooking.And I don't know if I should add ventilation to cool them off or if they lik...

Hey listen I have a vinyl greenhouse that is full of cacti. Lately the temps are getting pretty high and when the door is opened it you know it is getting hot.I can touch the soil on larger cacti and it's like it is cooking.And I don't know if I should add ventilation to cool them off or if they lik...

What does that say? Bone, Me,-,-
That looks tacky!

What does that say? Bone, Me,-,-
That looks tacky!

The light should be far enough away that the soil will not dry out that fast,
seedlings burn easy!