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Water Mint · Mentha aquatica

Why are my water mint leaves turning yellow?

Water mint loves moisture, but yellowing leaves often signal that the roots are struggling with the water balance. Check your soil moisture levels first, as this plant is very sensitive to stagnant or sour water.

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yellow leaves on a plant
Photo: Trio3D, CC BY-SA 4.0

Check these first

  1. Smell the water or soil for any signs of decay.
  2. Check the water level to ensure the roots are not drying out.
  3. Inspect the undersides of leaves for any signs of pests.

Likely causes

  1. Poor water quality

    Most likely

    How to tell: The leaves turn yellow starting from the bottom of the plant, and the water in the container may smell slightly off.

    What to do: Change the water in your container every 3 to 5 days to keep it fresh. If the plant is in soil, flush the pot with clean water to remove salt buildup.

  2. Nutrient deficiency

    Possible

    How to tell: Older leaves turn pale yellow while the veins remain green, indicating the plant is hungry.

    What to do: Apply a balanced liquid fertilizer diluted to half strength once a month during the growing season. Ensure the fertilizer is safe for aquatic environments if your plant is in a pond.

Yellow leaves on other plants

Find out what's wrong with your water mint

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 very bottom leaves to yellow and drop as the plant grows taller. Worry if the yellowing is spreading rapidly to the top of the plant.

Stopping it coming back

Keep the water fresh and provide consistent, bright light to maintain healthy growth.

Water Mint: yellow leaves? Check yours with a photo

Every plant is a little different. Take a photo of your water mint 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.

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Questions people ask

Should I cut off the yellow leaves?
Yes, snip them off with clean scissors to help the plant focus its energy on new growth.
Can too much sun cause yellowing?
Yes, if the plant dries out too quickly in full sun, the leaves can bleach and turn yellow.

More problems with Water Mint

Back to the Water Mint 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.