Check these first
- Press the base of the stems to see if they feel soft or hollow.
- Stick your finger 2 inches into the soil to check for dampness.
- Lift the pot to see if water is trapped in the saucer.
Likely causes
Overwatering
Most likelyHow to tell: The base of the stems feels soft or squishy to the touch and may turn yellow or brown. The soil stays wet for more than 14 days.
What to do: Stop watering immediately and let the soil dry out completely. If the rot is advanced, remove the plant from the pot, trim away black or slimy roots, and repot in fresh, well draining cactus mix.
Poor drainage
PossibleHow to tell: Water pools at the bottom of the pot or the soil remains heavy and dense. The plant does not seem to drink water even after a long time.
What to do: Ensure your pot has large drainage holes at the bottom. Use a porous terracotta pot to help moisture evaporate faster from the soil.
Find out what's wrong with your rat's tail cactus
The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.
Scan with your phone's camera to get the app
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When to worry
If the stem is mushy all the way through or the rot has spread to the main body, the plant may be beyond saving. Firm, green stems are a sign of a healthy plant.
Stopping it coming back
Always let the top few inches of soil dry out completely before watering again. Use a gritty, fast draining soil mix designed for succulents.
Rat's Tail Cactus: root rot? Check yours with a photo
Every plant is a little different. Take a photo of your rat's tail cactus and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.
Scan with your phone's camera to get the app
Or go to pocketbotanist.app/get on your phone
Get the app · Or check it from a photo now, free
Questions people ask
- How often should I water my cactus?
- Water every 7 to 14 days depending on the light and temperature. Always check the soil dryness first rather than sticking to a strict calendar.
- Can I save a plant with root rot?
- If you catch it early and remove the damaged roots, you can often save it. If the rot has reached the main stem, you might need to take healthy cuttings to propagate a new plant.
More problems with Rat's Tail Cactus
- Why are there white fuzzy spots on my Rat's Tail Cactus?
- Why is my Rat's Tail Cactus growing long and thin?
- Why is my Rat's Tail Cactus not blooming?
- Why are my Rat's Tail Cactus stems turning yellow?
- Why are the tips of my Rat's Tail Cactus turning brown?
- Why is my Rat's Tail Cactus drooping?
- Why does my Rat's Tail Cactus have spots?
Back to the Rat's Tail Cactus guide
This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.

