We have a number of 12-15 year old golden barrel cacti in our yard. Recently, some have begun to spawn pups and others have not. Is there a reason why some do and others don't?
The Barrel Cactus is growing little Cactus pups and it is part of the natural growth pattern for this plant.
You can remove them and grow new plants.
Here is a few articles that have more information.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/removing-cactus-pups.htm
https://www.gardeningknowhow.com/ornamental/cacti-succulents/barrel-cactus/barrel-cactus-care.htm
I have a Cluster Golden Barrel cactus. If I remove 2 of the globes by cutting them, will the entire cactus die? This needs to be done to allow brick wall repairs behind the cactus. The plant is too large to move. We estimate it may weigh 300 lbs.
Yes, you can remove the pup. Here is information on how to.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/barrel-cactus/barrel-cactus-care.htm
https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/removing-cactus-pups.htm
Where the spines grow out has turned black. Can I save it?
It is possible that the cactus has been damaged by freezing temperatures, by sunburn, or by a fungal rot disease.
This article may help you determine what is wrong:
https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/cactus-going-soft.htm
We have a large (20" diameter) golden barrel that has lived in a pot for years. We want to place it in a succulent planting. My question is about the darkened, dried part of the plant. The soil has gradually washed away so that about 6" of trunk is exposed. Is it safe to bury this darkened trunk, or am I risking rot?
Make sure you orient the cactus in the same location that it is growing in the pot. Mark the south side and place the plant in it's new home in the same orientation.
The roots can be trimmed to not extend past the diameter of the cactus.
Make sure it is a well draining area, and not one that will hold or collect water.
Dig the shallow hole and plant the cactus deep enough to just cover the soil line on the cactus. Don't place it beyond this point on the cactus.
Tamp the soil and do not water for the first 2 weeks.
You may need to provide some shading for the first couple of months in it's new home.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/barrel-cactus/barrel-cactus-care.htm
how do you get a golden barrel cactus to grow pups?
Optimize care, as the Cactus would have in it's natural environment for the best chance of pups.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/barrel-cactus/barrel-cactus-care.htm
https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/removing-cactus-pups.htm
My cactus has gone a bit mushy and is dying. I'm very worried and don't know if it needs less water or more.
Over watering is the most common cause of the loss of a cactus.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/barrel-cactus/barrel-cactus-care.htm
I live in SW Kansas. I have a golden barrel approximately 35 years old and it has always been in a pot. It has become too large for me to move outside, but can I plant it in the ground without it freezing in the winter? Thank you.
Golden Barrel Cactus is hardy in zones 9-11. It would not be hardy outdoors in your growing zone.
Perhaps you could donate the Cactus to a business or Library that may have a larger space for the plant.