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corn speedwell · Veronica arvensis

Why are there spots on my corn speedwell leaves?

Spots on corn speedwell are often caused by fungal issues like powdery mildew, especially in humid conditions. Check the leaves for a white, dusty coating to confirm.

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spots on a plant
Photo: Scot Nelson, CC0

Check these first

  1. Look for a white, dusty residue on the leaves.
  2. Check if the plant is crowded by other foliage.
  3. Inspect the underside of the leaves for pests.

Likely causes

  1. Powdery mildew

    Most likely

    How to tell: White, powdery spots appear on the surface of the leaves and stems.

    What to do: Improve air circulation around the plant by spacing it away from others. You can treat it with a neem oil spray once a week until the spots disappear.

  2. Fungal leaf spot

    Possible

    How to tell: Small brown or black spots with yellow halos appear on the foliage.

    What to do: Remove the affected leaves immediately to stop the spread. Avoid getting water on the leaves when you water the soil.

Leaf spots on other plants

Find out what's wrong with your corn speedwell

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

Worry if the spots cover more than half of the leaves or if the plant starts dropping foliage. Minor spotting is manageable with quick treatment.

Stopping it coming back

Water at the base of the plant to keep leaves dry and ensure good airflow between plants.

Corn speedwell: spots? Check yours with a photo

Every plant is a little different. Take a photo of your corn speedwell 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

Is powdery mildew contagious?
Yes, it spreads through spores in the air. Keep infected plants isolated until they are fully treated.
Can I wash the spots off?
You can wipe leaves gently with a damp cloth, but that does not kill the fungus. Use a fungicide or neem oil for better results.

Guides to these causes

More problems with corn speedwell

Back to the corn speedwell 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.