WSU Extension


Cucumber, Pumpkin, Squash : Slugs
(revision date: 4/11/2018)

Slugs are common garden pests in western Washington. They resemble snails, but lack shells. They may vary in size from as little as 1/4" up to several inches in length, depending on age and species. Foliage of older plants is raggedly chewed, while younger plants may be totally consumed. Slugs leave behind a characteristic slime trail, which appears silvery when it dries. Slugs typically feed at night and do more damage during cool, moist weather.
Management Options

Non-Chemical Management
  • Encourage predators such as birds, garter snakes, frogs, ducks, and predacious ground beetles. Avoid use of broad-spectrum insecticides which kill beneficial insects.
  • Hand-pick and kill slugs when noticed.
  • Clean up weeds and debris which may provide shelter. Cut tall weeds and grasses around the garden and clean up rocks, boards, and other shelters.
  • Trap slugs with cans of stale beer sunk into the ground.
  • Use chemical baits with caution, as pets can be poisoned. Iron phosphate-based baits are safer for pets!
Select non-chemical management options as your first choice!

Chemical Management

Broadcast to seedbed around border and between rows. Do not apply directly to plants. NOTE: Lilly Miller Slug & Snail Bait is registered for use on CUCUMBER AND SQUASH ONLY.

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Caption: Slug damage and slime
Photo by: R.S. Byther
Caption: Brown slug
Photo by: C.R. Foss
Caption: Slug damage on iris
Photo by: A.L. Antonelli
Caption: Slug
Photo by: C.R. Foss
Caption: Slug damage on tulip
Photo by: A.L. Antonelli