Skip Laurel Yellowing and Holes: Diagnosing Nutrient, Water, and Pest Issues

A gardener planted skip laurels (Prunus laurocerasus 'Schipkaensis') last year. Now leaves are yellowing with holes, but no pests are visible. They want to identify the cause and treatment.

Common Causes of Yellowing

Cause	Symptoms	Solution
Nutrient deficiency	Uniform yellowing, poor growth	Slow-release evergreen fertilizer high in nitrogen and potassium
Poor drainage/overwatering	Yellowing, leaf drop, wet soil	Improve drainage with compost; mulch 2-3 inches; reduce watering
Winter burn	Brown/yellow edges, desiccated leaves	Prune damaged tissue; protect with burlap screen next winter
Pest damage	Holes, stippling, distorted growth	Inspect closely; treat specific pest (see below)

Watering Guidelines

• Fall/winter: Every 2 weeks if no rain
• Spring/summer: 1-2 times weekly, 1 inch per week
• Check: Soil should be moist 4-6 inches down, not soggy

Common Pests (Even If Not Visible)

• Aphids: Cluster on new growth; cause curling. Treat with insecticidal soap or neem oil.
• Scale: Bumps on stems; cause yellowing. Treat with horticultural oil in dormant season.
• Spider mites: Fine webbing, stippled leaves. Treat with miticide or strong water spray.
• Thrips: Silvery patches, black fecal spots. Treat with spinosad.
• Beetles: Shot-hole feeding. Usually minor; hand-pick if needed.

Disease Concerns

• Laurel wilt: Sudden wilting, death. No cure; remove infected plants.
• Fungal leaf spots: Circular lesions. Improve air circulation; avoid overhead watering.

Integrated Approach

1. Test soil drainage: Dig 12-inch hole, fill with water. Should drain in < 4 hours.
2. Apply 2 inches of mulch (bark, compost) keeping away from stems.
3. Water deeply once weekly (7 minutes at slow trickle).
4. Fertilize with slow-release evergreen formula in early spring.
5. Monitor weekly for pests; treat only if thresholds exceeded.

Follow-Up Treatment

If pests are confirmed, horticultural oil (Volck) preserves beneficial insects. Systemic options like Bayer Advanced Tree & Shrub provide longer control but affect pollinators. For fungal issues, prune for air flow and apply copper fungicide.