Cactus with a yellowing base


HI There,

I was given this cactus about 4 years ago and have done my best to care for it but I am very limited in my knowledge about plants. I try not to water too much (once a month maybe twice in a month in the summer) as I know they don’t like water. My cactus seems to be becoming more and more yellow as time passes on. It seems to me from what I have gathered it’s from over watering. Would it be wise to repot this cactus? or at least give it fresh soil? or would fertilizer help? or do you think that if I stop watering for a month or two it should solve the issue?

It sits in the window but I live in a basement so I don’t get a lot of (if any) direct sunlight. The windows are very old so they definitely have air leakage which means this area might get pretty cold in the winter. Should I move the cactus away from the window?

Hopefully it’s savable, I think it’s beautiful. It has always grown so the growth hasn’t stopped, hopefully this is a good sign.



Thanks for contacting Toronto Master Gardeners.  Given the fact that your cacti is yellowing from the middle of the plant and is brown at the soil line, it probably has root rot.  This is something that is very easy to do and many cactus plant owners lose their plants this way. Cacti need very little water in the winter.  The soil should be completely dry before it is watered. The fact that it is near a drafty window with little sunlight slows down the process of the plant drying out.  You could remove the plant from the pot to inspect the roots.  If they are dark and soggy, it might be difficult to save the plant.  Sometimes when the damage is not too extensive, you can cut away the rotting parts from the roots and stem, let it dry out and then repot it in soil formulated specifically for cacti in a pot with good drainage. Another thing to consider is where to position the plant. It might be better to place any cacti you have away from the window and under a grow light so it receives sufficent light.

For more information about cacti and root rot please review the following resources:

Growing Cacti and Other Succulents – A Toronto Master Gardeners Guide

April 11, 2021