Q.indoor christmas cactus
I have had this Christmas cactus for 3 years. It was my mom’s; she passed 3 yrs ago. It is in a 6 inch pot, no drain holes, but I’m sure there are stones in the bottom of it. Should I repot it or leave it alone until it starts to look stressed? It looks healthy and blooms about every 2 months. It explodes in December/January. This cactus just looks so big to be in a 6 inch pot, but it looks healthy.
When your plant is done blooming it may be time to repot.
The lack of drainage holes is concerning, but you have done a great job in not overwatering it.
Care must be taken that the plant never sit in soggy soil as this will lead to root rot.
Here are a few articles for you with more information.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/christmas-cactus/advice-for-christmas-cactus-care.htm
https://www.gardeningknowhow.com/ornamental/cacti-succulents/christmas-cactus/repotting-christmas-cactus.htm
https://www.gardeningknowhow.com/ornamental/cacti-succulents/christmas-cactus/christmas-cactus-pruning.htm