Holes in hosta leaves: causes and fixes

The most common cause of holes in hosta leaves in the eastern United States is slugs, followed by deer browse (especially in suburban areas), with earwigs and cutworms as less frequent contributors. The hole pattern, timing, and location of damage are the best diagnostic clues. I

By Thomas Joseph Published 2026-06-11 Updated 2026-06-13 Reviewed by Thomas Joseph 7 min read

Hostas are among the most commonly damaged shade garden plants, and holes in the leaves are the most common symptom. The challenge: four different culprits produce holes, and each has a different solution. Applying slug bait when deer are the problem, or deer repellent when slugs are eating, wastes time and money.

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Quick diagnostic table

Hole type	Timing	Additional clues	Most likely cause
Ragged holes, large, along leaf edges	Overnight	Stripped stems; stems bitten off; no slime	Deer
Irregular holes anywhere on leaf, including center	Overnight, spring–fall	Slime trails visible in morning; holes often near soil	Slugs
Smooth-edged, round holes	Day or night	No slime; small dark pellet frass nearby	Earwigs
Seedlings cut at base; holes in tender new growth	Early spring	Larvae may be found in soil	Cutworms
Ragged holes with brown edges	Daytime	Holes develop mid-season, not spring	Deer browse during dry spells

Reader questions

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How do I tell slug holes from earwig holes?

Slug holes tend to be irregular in shape, often along the center of the leaf, and accompanied by slime trails on close inspection. Earwig holes are rounder and more cleanly cut. The most reliable test is nighttime inspection with a flashlight — slugs will be visible; earwigs hide more effectively but can also be found.

Do copper rings around hostas work?

Per UC IPM, "copper barriers can provide some protection" but are impractical for established landscape hostas because the copper ring needs to encircle the entire crown without gaps. They work better for individual pots than for ground-planted hostas. Iron phosphate bait applied around the perimeter is more practical for landscape plantings.

Is it worth replanting hostas that deer keep eating?

If deer pressure is consistently high, replanting the same species repeatedly while doing nothing about deer access is a losing strategy. The practical options are: fence, systematic repellent program (committed to reapplication), or plant deer-resistant alternatives (astilbe, ferns, bleeding heart, pulmonaria, epimedium) in high-pressure areas.

When should I apply iron phosphate slug bait?

Apply when conditions favor slug activity: after rain or irrigation, when temperatures are above 40°F. Per Penn State Extension, slugs "become active above 40°F and are most active at temperatures of 50–65°F." Apply in the evening so the bait is fresh when slugs emerge. Don't apply before hot, dry weather that kills slugs anyway.

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Holes in hosta leaves: causes and fixes

Quick diagnostic table

Holes in hosta leaves: causes and fixes

Quick diagnostic table

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