I've had this cactus for a few months, I don't remember what it was labeled, but I think it's an old man? He's been looking really good, but I got a weird feeling about him today, so I checked the bottom and it's dry and brown!
Is it dying?

It looks fine to me. I'd leave it out of the soil a few days to callous over the roots. Then re-plant it in good cactus soil and don't water right away. Let it sit a week or two and then only water a very small amount.
I killed a lot of these by over watering them. They take very little water to grow and be happy and yours looks fine to me.
Good luck with it!

Here is one of mine that has been growing for about 14 years now.



Here is another one that has been growing about 11 years.

To the extent the bottom is brown, it looks like it has been buried under the soil. I wouldn't worry about the brown part if it is firm. But do try to avoid burying above-ground cactus parts when you repot or transplant. Try to maintain the status quo that way when you seat the plant.

And don't water any cactus right after bare-rooting it, wait a few days to a week.

Karen, your oldies are gorgeous. Do they flower and make fruit?

So far they've never flowered, Baja. I keep wondering how long it will be or if they'll ever bloom. I'm just happy that I finally figured out how to grow them without overwatering them. I must have killed 4 or 5 before I got smart!

Mine is over 50 years old and I've never seen it bloom. The guy in Manteca (Mr. Poots) had them blooming every year.

The one here started a couple years ago and seems to do it every year. But no fruit. Still looking for love, apparently.

What a beauty! How wonderful to see one bloom. Hopefully one day you''ll see fruit. I wish we knew the trick to getting them to bloom.

Well that's a disappointing bloom. If I have to wait 60 years (Oh, its 60 years old, not 50) to see mine bloom, I want it to look like a giant red Echinopsis flower.

I think it's pretty neat, considering how rare they seem to be! They can't all be Echinopsis blooms!

It's a nice color combination, nothing spectacular. Usually in October. I was kind of more interested in fruit, really.

Well, get out your little paint brush!

I'm waiting for Oreocereus #2 & 3 to do their thing. They are different species but I am definitely getting out the paintbrush if and when they flower in synchrony. I don't think the one flowering plant (celsianus) is self fertile.

In orchid culture, we save pollen to cross pollinate two plants not in bloom at the same time. If properly treated, the pollen is good for a year or so. Is that an option in cactus?

Never tried that myself, but it is in theory possible. You have to keep it cold with very low humidity, I think. I remember the aloe people were doing that. Anyway, that would be beyond me. I love the paintbrush (it's fun to play bee, visually) but if you don't store the pollen right, it's useless down the road.

I also have an Old man myself, for about 8 years. It has never bloomed for me yet. I dont' know why. It gets enough light, but it stays outside in the winters in shaded place, getting sun, but not rain on him. The conditions are fine, but no bloom. @Lindsay_blinsnom, yours seems alright to me also, he's a fine Old man!

This old man cactus must be 50 yes old. The main stem has started to wilt. Can I re-plant the side shoots? Don't want to lose the whole thing

Yes absolutely. Take them off let the bottom callus before placing on soil. One the callus has formed place the cactus on sterile soil & using sterile pots then place in indirect light 8-10 hrs per day, 60' warm temps and soon they will root.
Boy I went thru a few cactus that ended up having the same fate after years of service. Rescue the side shoots and keep the cactus in the family.

Good luck.

@Lindsey_blinsmon, how is your old man doing now?
@Chase901, do as Bumplbea said. You should be able to save parts of it to grow on. I literally don't water them very much. Mine outside in AZ gets about a cup of water a month in summer, and none in winter, except for natural water from rains. The soil they are in is extremely well draining. They need to never stay wet for long.

Daisy your cactus doesn't look a day over 25!