Pocket Botanist
Check these first
- Assess the current light levels in your growing area.
- Check the distance between the plant and the nearest light source.
- Measure the ambient temperature near the plant.
Likely causes
Insufficient light
Most likelyHow to tell: The plant has long gaps between leaves and the stems look thin or weak.
What to do: Move the plant to a spot with brighter indirect light. If you are growing indoors, place it closer to a window or add a grow light for 12 to 14 hours a day.
High temperatures
PossibleHow to tell: The plant grows rapidly but looks thin and weak despite having decent light.
What to do: Keep your plant in a cooler area between 65 to 70 degrees Fahrenheit. Avoid placing it near heat vents or radiators.
Find out what's wrong with your thale cress
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
It is normal for the plant to stretch slightly as it prepares to bolt and flower. Worry if the stems are so weak they cannot support the leaves.
Stopping it coming back
Provide consistent, bright indirect light throughout the entire vegetative stage.
Thale cress: leggy growth? Check yours with a photo
Every plant is a little different. Take a photo of your thale cress 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
- Can I trim back a leggy Thale cress?
- It is better to adjust the light than to trim, as this plant does not recover well from heavy pruning.
- Will a leggy plant still produce seeds?
- Yes, but the plant may be weaker and produce fewer seeds than a compact, healthy one.
More problems with Thale cress
- Why are there white spots on my Thale cress leaves?
- Why is my Thale cress drooping?
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- Why is my Arabidopsis thaliana showing signs of root rot?
- Why are my Arabidopsis thaliana leaves curling?
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.