Holes In Hollyhock Leaves: Common Causes And Natural Solutions

Nothing ruins a hollyhock display faster than leaves full of holes. I’ve lost entire plants to overnight raids, and the culprits are usually the same: beetles, slugs, or earwigs munching through tender foliage.

The good news? You don’t need harsh chemicals to stop them. Simple barriers like copper tape or diatomaceous earth work wonders, and hand-picking pests at dusk is surprisingly effective.

Within a week of consistent effort, you’ll see new growth emerging unscathed. The plants recover fast once the attackers are gone, and the blooms keep coming all season.

Works for any hollyhock variety, whether in borders, containers, or cottage gardens. Here’s how to outsmart the invaders for good.

Why Leaves Develop Holes

Hollyhocks are classic garden favorites, but their broad leaves often fall victim to unsightly holes. The culprits range from hungry insects to environmental stress. Below are the most common causes, explained with clear, actionable insights.

🐛 Insect Feeding Damage

Japanese beetles, sawfly larvae, and Holeus weevils are frequent offenders. Japanese beetles chew irregular holes between leaf veins, often skeletonizing foliage. Sawfly larvae, resembling green caterpillars, devour leaf tissue from the edges inward, creating ragged holes. Weevils leave small, round punctures. Check undersides of leaves in early morning or evening to spot these pests in action.

🍄 Fungal and Bacterial Infections

While less common, pathogens like Alternaria or bacterial leaf spot can cause tissue death that appears as holes. These start as dark, water-soaked spots that expand and dry out, leaving gaps. Wet foliage and poor air circulation encourage these diseases. Remove and destroy affected leaves to prevent spread.

🌧️ Environmental Stress

Extreme weather—hail, heavy rain, or wind—can physically tear leaves, mimicking pest damage. Drought stress may also cause leaf edges to dry and crumble, creating a hole-like effect. Mulch and consistent watering help mitigate stress-related damage.

How to Fix the Problem

Here are practical fixes for the most common causes of leaf damage, along with prevention tips to keep your hollyhocks thriving.

🐛 Japanese Beetles → Handpick or Use Neem Oil

If you spot metallic green-and-copper beetles chewing irregular holes, act fast. Handpick them off in early morning when they’re sluggish and drop them into soapy water. For larger infestations, spray leaves with neem oil (mix 1 tbsp oil + 1 tsp dish soap in 1 quart of water) every 5–7 days. Prevent future attacks by applying beneficial nematodes to the soil in spring to target grubs before they mature.

🕷️ Spider Mites → Blast With Water or Insecticidal Soap

Tiny webs and stippled yellowing? Spider mites thrive in dry conditions. Spray plants vigorously with water to dislodge them, or apply insecticidal soap (1 tbsp per quart of water) weekly until gone. Prevent outbreaks by misting leaves regularly and keeping the garden weed-free to reduce hiding spots.

🍄 Fungal Diseases (e.g., Rust) → Remove Leaves and Improve Airflow

Orange or brown spots with holes? Fungi like rust spread in wet conditions. Prune infected leaves immediately and destroy them (don’t compost). Apply a baking soda spray (1 tbsp baking soda + 1 tsp oil + a few drops of soap in 1 gallon of water) every 10 days. Prevent fungus by spacing plants 18–24 inches apart and watering at the base to keep foliage dry.

🐌 Slugs and Snails → Set Up Barriers or Traps

Large, ragged holes overnight? Slugs and snails are the culprits. Create a barrier with crushed eggshells or copper tape around plants. Set out beer traps (bury a shallow dish filled with beer at soil level) to lure and drown them. Prevent visits by removing debris and watering in the morning so soil dries by evening.

Pro tip 💡: Healthy plants resist pests better! Boost hollyhock resilience with compost tea or a balanced organic fertilizer every 4–6 weeks.

Frequently Asked Questions