Home Gardening Holes in Potatoes (Wireworm Pest Management)

Holes in Potatoes (Wireworm Pest Management) – GIY Plants

Wireworm creating holes in potatoes.

We occasionally discover the unexpected in our horticultural endeavors: holes in our potatoes. These anomalies are not merely aesthetic flaws. They hint at underlying problems that could compromise the health of the entire potato crop.

Wireworms and Holes in Potatoes

A primary culprit behind holes in potatoes is the wireworm. As the larval stage of click beetles, wireworms are yellowish to brown and feed on the roots of various plants, including our beloved tubers. Wireworms move through the soil, creating tunnels or burrows as they feed, leading to the unsightly holes we find.

Slug Damage

Slug eating holes in potato.

Another offender is the common garden slug. These pests don’t tunnel but nibble on the potato’s surface, leaving small, shallow holes. The damage they cause can be severe, especially during periods of high rainfall or in weedy garden areas that provide them with ample cover.

Nematodes and Insects

Potatoes are also susceptible to nematode infestations, particularly by the aptly-named potato tuber nematode. Meanwhile, other insects, such as the Colorado potato beetle and flea beetles, can cause damage to potato leaves and developing tubers, contributing to the hole problem.

Hollow Heart in Potatoes

Potato cut in half showing a condition called hollow heart.

However, not all holes are pest-related. “Hollow heart,” a condition known in horticulture circles, is an internal discoloration and splitting of the potato tuber, resulting in hollow spaces. It often occurs due to an abrupt change in growing conditions, such as inconsistent soil moisture levels.

Managing the Problem: Pest Management Strategies

Given the range of potential culprits, effective pest management is critical. From crop rotation to reducing wireworm populations to targeted use of insecticides, we can employ several strategies. Some gardeners have succeeded with wireworm traps or using bait crops in areas prone to infestation.

Checking for Wireworms

Cut potato showing a wireworm eating a hole through it.

Regularly checking for wireworms is also advisable. We can draw wireworms out by cutting a potato in half and burying it in the soil. If wireworms are present, they’ll burrow into the potato bait, revealing their presence.

Combatting Slugs

For slugs, removing their preferred habitats and handpicking can be effective strategies. During dry periods, slug populations naturally decline, reducing their impact on our potato crops.

Mitigating Hollow Heart

To prevent hollow heart, we need to ensure consistent growing conditions. This includes regular watering and avoiding over-fertilization, which can promote rapid, uneven tuber development.

Are Potatoes with Holes Safe to Eat?

Potatoes with holes caused by wireworms or slugs are generally acceptable to eat once the damaged areas are removed. However, we should always check for discoloration or rot, which can indicate the presence of harmful bacteria.

Frequently Asked Questions

What are the causes of holes in my potatoes?

Various factors, including pests and diseases such as wireworms and aphids, can cause potato holes. These pests burrow into the potatoes and create small holes or tunnels.

What is a wireworm?

Wireworms are the larval stage of click beetles. They are thin, elongated worms that can cause damage to root crops, including potatoes.

How do wireworms eat potatoes?

Wireworms burrow into potatoes and feed on the tubers. They move through the soil depending on temperature and feed on the potatoes as they grow.

How can I avoid planting potatoes with wireworms?

To avoid planting potatoes with wireworms, you must rotate your crops and plant them in a different area every year. This helps to reduce the population of wireworms in the soil.

What other pests can cause holes in potatoes?

Apart from wireworms, potato tuber nematodes can also cause holes in potatoes. 

How can I prevent aphids from damaging my potato plants?

You can use insecticidal soaps or organic pest control methods to prevent aphids from damaging your potato plants. 

What is a hollow heart in potatoes?

A hollow heart is a condition in potatoes where a hollow cavity develops in the center of the tuber. It occurs due to several factors, including irregular growth and environmental conditions during the growing season.

Can wireworms cause hollow heart in potatoes?

It is unlikely for wireworms to cause hollow hearts in potatoes. The hollow core usually occurs due to uneven moisture levels, temperature fluctuations, and other environmental factors during tuber development.

When is the best time to harvest potatoes?

The best time to harvest potatoes is typically when the foliage has started to die back and turn yellow. This indicates that the potatoes have reached maturity and are ready to be harvested.

Are wireworms present year-round?

Wireworms are usually more active in the soil during the spring when soil temperatures are warmer. However, they can be present year-round, depending on the climate and soil conditions.


As master gardeners, our role is to adapt and respond to the challenges of pests and environmental factors. By understanding the causes behind holes in our potatoes, we can ensure the health and productivity of our crops.

Join Us

Sign up to get all the latest gardening tips!