I agree. Be very cautious when wintering since they are rot prone.

Another thought is that the growth point was damaged and the new pup/growth point that formed overtook the first in size. Although the cacti of mine that grew like this never damaged its main growth point or grew a new pup

My theory is that when the older base of the cactus corked over, the corking was thick enough to prevent it from expanding from the new growth. Thus, it growing upward and outward like a mushroom head. Any opinions about that theory?

I have had some other species do this in my collection, also. I have suspected it was the way it went dormant, but never figured out the true reason behind it. Mine are grown outdoors in full sun and are under grow lights inside in the winter. They are kept dry in the winter

Thank you, Steve johnson,, I will do that.

I will do that. Thank you

I have unknown spots that form on my opuntia. Some areas are heavier than others. I have had it on the cactus for at least two years and does not appear to affect its health. It is not mealy bugs and does not appear to be scale. Also it does not spread to other cactus. It sort of resembles the spots...

Thank you Jerry the plater.

Thank you mrxeric! Your information and tips was very helpful.

I have recently grafted a mamm. Ortega on a pachanoi.
I am having a tough time locating tips and info about grafting onto pachanoi and also the care tips after freshly grafting a cactus.
Does anyone have any information on grafting and its aftercare?

I found the link. https://www.cactuspro.com/biblio/en:accueil

I remember there was a web site where you could look up free cactus and succulent books by author or title. I can not remember the name of that website

Does anyone remember the name of the website?

I am growing a variety of cacti and succulent seeds. Most of them are cactus such as MAMMILLARIA, thelocactus, ariocarpus, trichocereus, and some mixed cacti seeds. The succulents are mostly the caudiciforms.

I am using a heating pad with a thermostat to sow cacti seeds.
I have read that some say to leave the mat on 24/7.
Should i run the heating mats continuously or is it better to run it set to a certain temperature? If you run it at a certain temperature, what is the ideal temperature to sow seeds?

I am rooting some miscellaneous cacti and succulents. Has anyone used a heating pad under the cuttings and have had successfull results? Will it speed up the rooting of cuttings?
I do use rooting hormone, but I have some cuttings which are very slow to root.