Holes in Skip Laurel Leaves: Identification, Causes, and Solutions

Skip laurel (Prunus laurocerasus) is a handsome broadleaf evergreen shrub prized for its lustrous foliage and fast dense growth habit. However homeowners often notice unsightly holes developing on the leaves, especially on lower branches. This damage, known as shothole, can diminish the ornamental value and curb appeal of skip laurel hedges and foundation plantings.

In this comprehensive guide, we’ll examine the common causes of shothole damage in skip laurels and provide effective treatment methods to restore plant health and beauty With proper identification, adjustments to care, and timely interventions, you can resolve holes in leaves and get your laurel looking lush again

What Causes Holes in Skip Laurel Leaves?

There are three primary causes of shothole injury to skip laurel foliage

Fungal Leaf Spot Diseases

Several foliar fungal pathogens can infect skip laurel, including cercospora leaf spot (Cercospora spp.), phytophthora leaf spot (Phytophthora spp), and anthracnose (Colletotrichum spp.). These fungi thrive in warm, humid conditions. Infected leaves first develop distinct spots that enlarge and merge, eventually turning brown and breaking down to create shothole symptoms as the dead tissue drops out.

Bacterial Leaf Spot

Xanthomonas arboricola pv. pruni, the bacterium which causes bacterial spot, is another potential culprit. Initial water-soaked lesions on leaves become necrotic with yellowing halos. The affected spots then fall away leaving holes, mimicking fungal shothole damage.

Environmental Stress

Abiotic factors like insufficient water, extreme temperatures, compacted soil, too much or too little light, and nutritional deficiencies can stress plants. This stress can predispose skip laurel to attack from opportunistic fungal and bacterial pathogens, resulting in shothole injury.

In many cases, it’s the interaction of biotic infections and abiotic stresses that brings on shothole damage in skip laurels. Getting both factors under control is key for prevention and treatment.

How to Treat Shothole Damage in Skip Laurels

If your laurel hedge displays early symptoms or isolated cases of shothole damage, prompt action can get the problem in check:

• Improve air circulation and light penetration by selective pruning to open up the inner canopy. This reduces humidity levels unfavorable for fungal and bacterial diseases.

• Apply preventive fungicide sprays containing chlorothalonil, myclobutanil, or copper regularly as a protective barrier. Follow all label instructions carefully.

• Boost plant vigor with a balanced 10-10-10 fertilizer to strengthen disease resistance. Fertilize in early spring and again in midsummer.

• Remove and dispose of fallen leaves and prune out any dead or obviously diseased branches. This limits spread of inoculum.

• For bacterial shothole, trim back well into healthy wood, sterilizing tools between each cut with isopropyl alcohol.

• Consider replacing susceptible varieties like ‘Zabeliana’ and ‘Herbergii’ with disease-resistant cultivars such as ‘Otto Luyken’, ‘Schipkaensis’, and ‘Etna’.

If shothole damage is already extensive, more aggressive renewal pruning is required:

• In early spring before new growth starts, cut each stem back to just above a healthy bud. Remove and destroy all debris.

• As regrowth occurs, apply fertilizer and fungicides on a preventive schedule as described above.

• Be prepared to prune again next spring if needed, and then annually thereafter for maintenance. Keep plants well-irrigated during regrowth. Healthy, vigorous new foliage will replace damaged leaves.

Cultural Practices to Prevent Laurel Shothole

Once you’ve tackled existing shothole damage, focus on prevention so your efforts aren’t in vain:

• Select a sunnier site. Skip laurels prefer morning sun with afternoon shade rather than deep shade. Insufficient sunlight leads to weaker growth vulnerable to pests and diseases.

• Space plants properly. Allow 2-3 feet between shrubs and 4-6 feet between hedge plants for airflow.

• Improve drainage in compacted clay by amending with compost or peat moss to create a better growing environment.

• Water correctly. Allow soil to partially dry out between irrigations. Overwatering encourages fungal and bacterial pathogens.

• Apply 2-3 inches of organic mulch to help regulate soil moisture and temperature.

• Fertilize annually with a balanced organic or slow-release formula to maintain plant vigor.

• Monitor routinely for early symptoms or abnormalities indicating shothole or other problems. Early intervention improves success of treatments.

• Improve airflow by thinning inner branches. This keeps humidity down inside plant canopies, deterring fungi.

• Avoid planting other susceptible Prunus species like cherry laurel nearby.

• Have patience during rehabilitation. It takes time for new healthy foliage to replace damaged leaves. Persistence with cultural methods, fungicides, and proper pruning will restore beauty. Prevention is easier than cure!

Identification of Shothole Damage

Accurate identification of shothole injury is important since treatment methods vary depending on the cause. Here’s how to discern the differences:

Fungal shothole – Distinct leaf spots with dark borders expand and coalesce before affected tissue dies and drops out leaving holes. Traces of fuzzy fungal growth may be visible on spots. More prevalent during cool, wet weather.

Bacterial shothole – Initial water-soaked lesions on leaves become necrotic and dry with yellowing edges. Dead tissue then falls away leaving holes. More active in warm, humid conditions.

Environmental shothole – Random, scattered holes between leaf veins result from generalized necrosis and tissue death. Not associated with defined spots or lesions. Worst during periods of drought or extreme heat.

Pest damage – Jagged holes along leaf edges or margins result from caterpillar and insect feeding. Targeted treatment of pests required.

Mechanical injury – Similar to pest damage but holes and notches are restricted to site of impact from hail, blown debris, etc. No need for pest control.

By identifying the specific cause, you can tailor solutions to resolve the shothole problem and restore the beauty and integrity of your skip laurel hedge.

Frequently Asked Questions About Skip Laurel Shothole:

What causes holes in skip laurel leaves?

The main causes are fungal leaf spot diseases, bacterial leaf spot, environmental stresses, and mechanical damage. Insect pests may also sometimes feed on leaves producing holes.

What are the small holes in my laurel leaves?

Small holes or shothole symptoms are usually caused by fungal pathogens like anthracnose, bacterial leaf spot, or abiotic stresses like drought. Accurate identification of the cause is needed to treat appropriately.

How do I treat holes in laurel leaves?

Treatment involves improving growing conditions, pruning out affected foliage, applying preventive fungicide sprays, and replacing susceptible varieties with disease-resistant cultivars if needed.

Why are there holes in my new laurel leaves?

Holes in new foliage may indicate a chronic, ongoing problem like bacterial leaf spot or conditions favoring fungal diseases. Ensure adequate spacing, air circulation and drainage. Disinfect tools between prunings and apply bacterial sprays.

What insects make holes in laurel leaves?

Caterpillars, leaf-feeding beetles like vine weevil, and some moths can cause hole-type damage. Check for insects on undersides of leaves and apply selective insecticidal soap sprays if found. Exclude environmental causes first.

By correctly identifying causes and implementing cultural prevention combined with prompt targeted treatments, holes and shothole damage in skip laurel can be successfully resolved. Patience and persistence with appropriate solutions will get your hedge looking lush and hole-free once again.