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Parsnip · Pastinaca sativa

Why are there bugs on my parsnip plants?

Parsnips are prone to the parsnip webworm, which loves to feed on your plant's foliage and flower heads. Check the tops of your plants for webbing or small caterpillars to confirm this is the culprit.

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

pests on a plant
Photo: Jules Verne Times Two, CC BY-SA 4.0

Check these first

  1. Inspect the flower heads for silken webbing.
  2. Look for small caterpillars hiding within the folded leaves.
  3. Check the base of the plant for signs of tunneling.

Likely causes

  1. Parsnip webworm

    Most likely

    How to tell: You will see silken webs binding the leaves or flower heads together. Small larvae will be visible inside these webs.

    What to do: Pick off the caterpillars by hand if the infestation is small. For larger issues, use a spinosad based spray according to the label instructions. Remove and destroy any heavily infested flower heads to prevent further spread.

  2. Carrot rust fly

    Possible

    How to tell: The leaves may look stunted or discolored, and you might find tunnels in the roots when you harvest. This pest is attracted to the scent of damaged foliage.

    What to do: Cover your rows with floating row covers early in the season to prevent flies from laying eggs. Avoid thinning your parsnips during the day when flies are active to keep the scent down.

Pests on other plants

Find out what's wrong with your parsnip

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

Small amounts of damage are usually fine, but heavy webbing can ruin your harvest. Take action as soon as you see the first signs of webs.

Stopping it coming back

Use floating row covers from the time of planting to keep adult insects away from your crops.

Parsnip: pests? Check yours with a photo

Every plant is a little different. Take a photo of your parsnip 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 parsnips that had webworms?
Yes, as long as the root itself is healthy and not damaged. Just trim off any affected foliage or flower stalks before cooking.
Are these pests harmful to humans?
No, they are strictly garden pests that target the plant. They do not bite or sting people.

Guides to these causes

More problems with Parsnip

Back to the Parsnip 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.