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Jerusalem artichoke · Helianthus tuberosus

What are these orange spots on my Jerusalem artichoke leaves?

Rust is a common fungal issue for Jerusalem artichokes, especially in damp or humid weather. Check the leaves for small, powdery spots that look like rust.

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spots on a plant
Photo: Scot Nelson, CC0

Check these first

  1. Examine the underside of the leaves for orange or brown spots.
  2. Look for a white powdery film on the top of the leaves.
  3. Check if the plants are crowded and lack airflow.

Likely causes

  1. Rust fungus

    Most likely

    How to tell: You will see reddish brown or orange pustules on the undersides of the leaves. Over time, these spots can cause the leaves to turn yellow and drop off.

    What to do: Remove and destroy any infected leaves immediately to stop the spread. Improve air circulation by thinning out crowded plants.

  2. Powdery mildew

    Possible

    How to tell: A white, dusty coating covers the surface of the leaves. It often happens when the air is humid and the plants are too close together.

    What to do: Prune back some of the foliage to allow better airflow. Apply a fungicide containing sulfur if the condition spreads to most of the plant.

Leaf spots on other plants

Find out what's wrong with your jerusalem artichoke

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 spots cover more than half of the foliage, the plant will struggle to produce energy for the tubers. Treat it as soon as you notice the first few spots.

Stopping it coming back

Water at the base of the plant to keep the leaves dry, and space your plants at least 18 to 24 inches apart.

Jerusalem artichoke: spots? Check yours with a photo

Every plant is a little different. Take a photo of your jerusalem artichoke 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

Can I eat the tubers if the leaves have rust?
Yes, the tubers are safe to eat. The fungus only affects the foliage and stems.
Should I cut the whole plant down?
Only if the infection is severe and the plant is dying. Otherwise, just remove the worst leaves.

Guides to these causes

More problems with Jerusalem artichoke

Back to the Jerusalem artichoke 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.