Pocket Botanist
Check these first
- Check if the soil feels soggy or swampy.
- Inspect the bulb for soft or foul smelling spots.
- Ensure your pot has drainage holes at the bottom.
Likely causes
Overwatering
Most likelyHow to tell: The soil stays wet for days and the bulb feels soft or mushy when touched.
What to do: Stop watering immediately and let the soil dry out completely. If the bulb is mushy, you must dig it up and discard it as it cannot be saved.
Poor Drainage
Most likelyHow to tell: Water pools on the surface of the soil or the pot lacks drainage holes.
What to do: Repot the bulb into a container with plenty of drainage holes. Use a gritty, well draining soil mix that contains extra perlite or sand.
Find out what's wrong with your ornamental onion
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.
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When to worry
If the bulb is soft and smells bad, it is likely too late to save it. It is normal for the foliage to start dying back naturally after the bloom cycle ends.
Stopping it coming back
Always plant your alliums in well draining soil and wait until the top few inches are dry before watering again.
Keep your ornamental onion healthy from here
Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked. Identification and a health check are free.
Questions people ask
- Can I save a bulb that has started to rot?
- If only a tiny spot is soft, you can try to cut it away and let the bulb dry for a few days before replanting. If the whole bulb is mushy, it is best to throw it away.
- How often should I water my alliums?
- Water them every 7 to 14 days during the growing season. Always let the soil dry out slightly between waterings.
More problems with Ornamental Onion
Back to the Ornamental Onion guide
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.