Holes in rose leaves: causes and what to do
The most common causes of holes in rose leaves are Japanese beetles (daytime skeletonizers), rose sawfly larvae (pale, translucent leaf-mining), and slugs (nighttime irregular holes). Deer cause wholesale removal of foliage rather than individual holes. Leafhoppers cause small, r
Rose foliage damage is one of the most visible mid-season garden problems, and the insect roster of rose eaters is longer than most plants. Identifying the specific culprit determines whether treatment will help or whether management focus belongs elsewhere.
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Quick diagnostic table
| Damage pattern | Timing | Additional clues | Cause |
|---|---|---|---|
| Skeletonized leaves (midrib and veins remain) | Daytime, June–August | Bronze-green beetles with white tufts visible | Japanese beetles |
| Small pale "windows" in leaves; leaf turns brown | Spring, May–June | Pale green larvae on undersides of leaves | Rose sawfly (Endelomyia aethiops) |
| Irregular holes, anywhere in leaf | Night | Slime trails possible; worst in cool, moist weather | Slugs |
| Entire leaf or branch stripped | Any time | No pest visible during day; deer sign nearby | Deer |
| Many tiny ragged holes in newer leaves | Day | Small pale wedge-shaped insects on stems | Leafhoppers |
| Large, clean-edged semicircular pieces removed from leaf margins | Day | Sweat bees or leafcutter bees hovering nearby | Leafcutter bees |
Cause 1: Japanese beetles (Popillia japonica)
Japanese beetles are the most destructive rose pest in most of the eastern US and one of the most visible — they feed in groups in broad daylight and skeletonize foliage rapidly.
What the damage looks like: Per Penn State Extension, "Japanese beetles skeletonize leaves by feeding between the veins, leaving a lace-like network of veins with the leaf tissue consumed." Flowers are also eaten. The damage occurs in June–August.
How to identify the pest: The beetles are 3/8 inch long, copper-colored with a metallic green head, and have white hair tufts along their abdomens. They cluster on roses, Japanese maples, linden, and many other ornamentals.
How to fix:
- Hand-pick: Per Penn State Extension, "hand-picking Japanese beetles from small plants early in the morning (when they are sluggish) is effective for light infestations." Drop them into soapy water.
- Pyrethrin or pyrethroid sprays: Per Penn State Extension, "pyrethrin provides knockdown of beetles on contact but has no residual; pyrethroids provide 2–4 days of protection." Spray the foliage in the evening to reduce risk to pollinators.
- neem oil: Azadirachtin-based neem disrupts beetle feeding but is less effective as a knockdown treatment.
- Do not use Japanese beetle traps: Per Penn State Extension, "bag traps attract more beetles than they catch" and can increase rose damage in trap-using gardens.
See our full guide on Japanese beetles and Japanese beetles on roses.
Cause 2: Rose sawfly (bristly roseslug)
The bristly roseslug (Endelomyia aethiops) is the larva of a sawfly wasp. Despite looking like a caterpillar, it is not treated with Bt (Bacillus thuringiensis (BT spray)) — Bt targets true caterpillars (Lepidoptera larvae), not sawfly larvae.
What the damage looks like: Per NC State Extension, "sawfly larvae skeletonize or window-feed on rose leaves, leaving the lower epidermis intact while consuming the green tissue." Early feeding appears as pale, papery window-patches; heavier damage progresses to full holes.
How to identify: Pale green, translucent-looking caterpillar-like larvae on the undersides of leaves in spring (typically May–June).
How to fix: Per NC State Extension, "insecticidal soap, neem oil, or spinosad sprays directed to the leaf undersides control rose sawfly effectively." Unlike with Japanese beetles, sprays applied to the foliage where larvae are feeding are very effective. The damage is typically limited to spring and rarely warrants more than one or two spray applications.
Cause 3: Slugs
Slug damage on roses follows the same pattern as on hostas: irregular holes anywhere on the leaf blade, occurring at night, with possible slime trails visible in the morning.
How to confirm: Nighttime flashlight inspection. Slugs feeding on rose foliage will be visible on the leaves.
How to fix: Iron phosphate bait (Sluggo (iron phosphate slug bait)) scattered around the base of rose bushes. Per UC IPM, "iron phosphate baits are effective against slugs and safe for use around all garden plants." Reduce mulch depth; keep the soil around rose canes clear of dense organic debris.
Cause 4: Deer
Deer don't create individual holes — they remove entire stems or large sections of foliage. Per Rutgers NJAES, roses are among the most preferred deer browse plants ("frequently severely damaged" in their rating).
How to confirm: Larger-scale damage; stems may be bitten off cleanly or with a characteristic jagged tear; damage often highest in early morning or evening.
How to fix: Fencing (6–8 feet for high-pressure areas), or a consistent repellent program using putrescent egg solid products. Per Penn State Extension, "repellents must be reapplied after rain and as new growth emerges." In very high deer pressure landscapes, roses are a poor investment without fencing.
Cause 5: Leafhoppers
Rose leafhoppers (Edwardsiana rosae) cause stippling and small holes in leaves from their feeding. Per NC State Extension, "leafhoppers cause pale stippling and eventual yellowing of leaves." The insects are small (1/8 inch), pale, and leap away when disturbed.
How to fix: Insecticidal soap or neem oil sprays. Per NC State Extension, "leafhoppers are generally a cosmetic pest that does not warrant aggressive treatment on established roses."
Cause 6: Leafcutter bees
Clean, semicircular pieces removed from leaf margins — as if cut with scissors — are the work of leafcutter bees (Megachile species). They use the leaf pieces to construct brood cells.
Important: Do not attempt to control leafcutter bees. Per Penn State Extension, "leafcutter bees are beneficial, native, solitary bees and important pollinators." The damage to roses is entirely cosmetic and does not harm the plant. No treatment is recommended or appropriate.
The honest tradeoff on rose pest management
Roses grown for ornamental purposes in the eastern US face a persistent roster of pests and diseases. An approach that makes sense: accept some pest pressure as the cost of growing roses, focus management efforts on the most damaging pests (Japanese beetles, black spot), and evaluate whether the plant is performing well enough to justify the maintenance investment.
Modern shrub roses with good disease and pest resistance (Knock Out, Easy Elegance, Canadian hardy series) require significantly less intervention than hybrid teas or climbing roses. If pest management is taking more time than the roses are worth to you, the honest solution is variety selection, not more spraying.
Common mistakes
| Mistake | What happens | Fix |
|---|---|---|
| Japanese beetle traps | Attracts more beetles; worsens damage | Don't use them; hand-pick instead |
| Bt spray for sawfly larvae | No effect (Bt targets caterpillars, not sawfly) | Use spinosad or insecticidal soap |
| Spraying insecticides during bloom | Kills pollinators | Spray at dusk when bees aren't active; avoid during bloom |
| Cutting back all damaged foliage | Weakens plant | Remove only when foliage is more than 50% damaged |
Frequently asked
Are Japanese beetles worse some years than others?
Yes. Per Penn State Extension, "Japanese beetle populations fluctuate with larval survival over winter, which depends on soil moisture during the summer egg-laying period." Wet summers produce more grubs; dry summers reduce populations. Applying milky spore granular or parasitic nematodes to lawn areas reduces grub populations over multiple seasons but effects are slow to accumulate.
When do Japanese beetles stop damaging roses?
Per Penn State Extension, "adult Japanese beetle activity lasts approximately 6–8 weeks, typically June through early August in the Mid-Atlantic." The damage intensity peaks in the first 4 weeks of the emergence period.
Can I use a systemic insecticide to prevent Japanese beetle damage?
Imidacloprid (sold as Bayer Tree & Shrub) applied as a soil drench protects rose foliage systemically from Japanese beetles for the season. However, per Penn State Extension, "systemic neonicotinoids applied to flowering plants can harm pollinators that visit flowers." Apply in fall or very early spring before flowering begins; avoid applications to blooming plants.
Sources
- Penn State Extension — Japanese Beetles on Ornamentals
- NC State Extension — Rose Sawfly and Leafhoppers
- UC IPM — Slugs on Ornamentals
- Rutgers NJAES — Landscape Plants Rated by Deer Resistance
Sources
- 1. Penn State Extension — Japanese Beetles on Ornamentals
- 2. NC State Extension — Rose Sawfly and Leafhoppers
- 3. UC IPM — Slugs on Ornamentals
- 4. Rutgers NJAES — Landscape Plants Rated by Deer Resistance