Skip to content
Pocket Botanist
Get the app

Thale cress · Arabidopsis thaliana

Why is my Arabidopsis thaliana not flowering?

This plant is less common for flowering in indoor settings, as it is primarily a model organism grown for research. It needs consistent bright indirect light and a stable environment to trigger its natural blooming cycle.

Not sure it's this? Check a photo of your plant for free

Check these first

  1. Verify the plant is receiving at least 10 hours of bright light.
  2. Check that the temperature remains steady throughout the day.
  3. Ensure the plant is not being over-fertilized with high nitrogen.

Likely causes

  1. Insufficient light

    Most likely

    How to tell: The plant looks leggy and stretches toward the light source. It shows no signs of developing flower stalks.

    What to do: Move the plant to a spot with more bright indirect light. If natural light is limited, use a grow light for 12 to 14 hours a day.

  2. Temperature fluctuations

    Possible

    How to tell: The plant is healthy but refuses to set buds. It may be sitting in a drafty area or near a heat vent.

    What to do: Keep the plant in a stable environment between 65 to 75 degrees Fahrenheit. Avoid placing it near air conditioning vents or radiators.

Other plants that won't flower

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.

Download on the App StoreGet it on Google Play

When to worry

It is normal for this plant to have a short lifespan, as it is an annual. If it has reached its maturity and still has not flowered, it may simply be the end of its cycle.

Stopping it coming back

Provide consistent light and stable temperatures from the start. Avoid moving the plant once it begins to develop buds.

Thale cress: not flowering? 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.

Download on the App StoreGet it on Google Play

Get the app · Or check it from a photo now, free

Questions people ask

How long does it take to flower?
Under ideal conditions, this plant typically flowers within 4 to 6 weeks. Patience is key as it develops.
Does fertilizer help?
A light application of a bloom-boosting fertilizer can help. Use it sparingly to avoid burning the roots.

More problems with Thale cress

Back to the Thale cress 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.