Pocket BotanistCheck these first
- Stick your finger into the soil to check for sogginess.
- Lift the pot to see if water is trapped in the bottom.
- Gently pull the plant out to inspect the roots for brown or mushy sections.
Likely causes
Overwatering
Most likelyHow to tell: The leaves will turn yellow and mushy, and the soil will smell sour or swampy. The stems may also feel soft near the base.
What to do: Stop watering immediately and let the top 2 inches of soil dry out. If the plant is in a pot without drainage holes, repot it into a container with plenty of holes using fresh, well draining potting mix.
Poor drainage
PossibleHow to tell: Water sits on the surface of the soil for a long time after you water. The plant looks sad even though the soil feels wet.
What to do: Mix perlite or coarse sand into your potting soil to improve airflow. Ensure the pot is not sitting in a saucer full of standing water.
When to worry
If the roots are black, slimy, or falling apart, the situation is critical. You may need to trim the dead roots and repot the plant to save it.
Stopping it coming back
Always allow the top inch of soil to dry out before watering again. Use a pot with drainage holes to ensure excess water can escape.
Not sure which one it is? Photograph your mandevilla.
This page lists the usual causes. Pocket Botanist looks at your actual leaf and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.
Questions people ask
- Can I save a plant with root rot?
- Yes, if you catch it early. Trim away the mushy roots, wash the remaining healthy roots, and repot in fresh, dry soil.
- How often should I water my Mandevilla?
- Water every 3 to 7 days depending on the temperature. Always check the soil moisture with your finger before adding more water.
More problems with Mandevilla
This article was generated with AI from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.