REPOTTING A CACTUS
I have a \"red Moon \" cactus it is only about 4 in. tall with one large branch/arm from that arm there is a long string like root coming out and dangling in the air and on the counter.the root is about 12\" long. I also see roots coming up from the surface of the potting mix. it seems time to repot it but what do I do with the long root coming from the arm of the cactus? any ideas?
You may re-pot these arms at any time, however they are ok with crowding as well. So as for the root... If you want to plant that arm, it will give it a head start. If you don't. you can leave it or cut it. either way will be fine.
Here is an article on the care of these cacti: https://www.gardeningknowhow.com/ornamental/cacti-succulents/moon-cactus/moon-cactus-repotting.htm