Wireworm On Tomato Plants: How To Identify, Control & Prevent

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This is a comprehensive guide that will help you identify and control tomato wireworms in your home garden.

Let us find out more below!

What Is Wireworm And How Does It Harms Tomato Plants?

Wireworms are the larvae of the click beetles that live in the soil. They are shiny, slender, wire-like, and hard-bodied about ¼ to 1 ¼ inch.

Like cutworms, these worms bite through tender roots and stems of tomato plants at the soil level.

How To Confirm That Wireworm Is Troubling Your Tomato Plants?

The different characteristics that will help you identify wireworms are the yellow colouring of the plant parts above ground, poor germination, damaged seedlings, and roots.

One tip to identify wireworms is by burying carrot pieces on the surface about three inches deeper closer to the tomato plant.

Check the carrot pieces every two days for holes due to wireworms.

Natural Ways To Control Wireworm On Tomato Plants

Wireworms are not easy to control. The most effective natural way to control wireworms is by releasing beneficial nematodes into the soil to kill them.

Method 1- Release Beneficial Nematodes

Beneficial nematodes are microscopic, soil-dwelling roundworms that may be used to kill wireworm larvae. One pint with about 10 million active units treats about 550 square feet of planting area.

  • Prepare beneficial nematodes– Beneficial nematodes come as granules and gels. Read the manufacturer’s instructions and prepare the formulations.
  • Moisten the soil– Water the treatment area with ¼ to ½ inch before applying the solution.
  • Spread the solution– Spread the solution over the infected area using a garden sprayer or watering.

Physical Ways To Control Wireworm On Tomato Plants

The most effective physical method to control wireworms is by placing bait balls using germinating beans, oatmeal, and potatoes. It helps to trap the wireworms and kill them.

Method 1- Bait The Wireworms Using Germinating Beans

Baits using germinating beans can be planted about two to four inches deep at about 3-10 feet intervals. It attracts the wireworms and helps to trap them.

  • Plant the bait– Dig trenches about two to four inches deep. Fill the planting holes with a mixture of germinating peas, beans, or corn. Cover them with a board or tile.
  • Uncover the baits– Remove the baits after 2-3 weeks and collect the wireworms. Kill the collected worms and toss the infested baits in the trash.

Method 2- Bait The Wireworms Using Flour

Bait balls may also be created using oatmeal and honey for trapping and determining the extent and location of the pests. The trapped wireworms may be handpicked and killed.

  • Prepare bait ball– Mix one to 1 ½ cups of wheat flour or oatmeal, 2 tablespoons of honey, and add little water to make a ball.
  • Bury the balls– Put the balls in the ground or mesh bag. Place them in 4-6 inch deep holes. Check every four to five days to collect wireworms.
  • Kill the wireworms– Pick the trapped wireworms and kill them.

Here is a useful video on making bait balls using flour:

Method 3- Spike The Soil

Spiking helps eliminate the wireworms that dwell near the soil surface using a sharp tool.

  • Choose the spiking tool– Choose the spiking tool about at least two inches in length. You may also use a garden fork, spike aerator, or plug aerator for spiking the soil.
  • Spike the soil– Make holes about two to six inches apart using the spiking tool. It helps in killing the wireworms near the soil. You may wait until the day after rainfall or water the soil before spiking.

Method 4- Use Potato Wireworm Traps

Potatoes may be inserted into the soil as bait to attract wireworms. It helps in trapping and collecting them.

  • Prepare potatoes– Cut the potato in half and poke a stick through the middle.
  • Bury the potato– Bury the spud about one inch deep. The stick should stand vertically as a handle.
  • Remove the worms– Pull the traps using a stick after two days and collect the wireworms. Kill the wireworms.

Click on this video to create baits using potatoes:

Chemical Ways To Control Wireworm On Tomato Plants

The different chemicals, including pyrethrin and bifenthrin can be used to control wireworms in home gardens. But, they should be used as a last resort only after confirming wireworms have caused damage.

Method 1- Spray Pyrethrin Solution

Pyrethrin acts as a repellant to foraging wireworms. It may help in controlling wireworm populations.

  • Prepare pyrethrin solution– Mix the concentrate in a gallon of water according to the manufacturer’s instructions. Transfer to the spray bottle.
  • Apply on the infected area– Spray on the infected area before planting or targeting wireworms. Take care when applied to new growth and tender foliage.

Method 2- Apply Bifenthrin Solution

Bifenthrin can be used to manage wireworm populations in home gardens.

  • Prepare bifenthrin solution– Read the manufacturer’s instructions and prepare the bifenthrin solution. These active ingredients are found either in granular or liquid formulations.
  • Apply on the soil– Apply as per directions on the soil before planting or at wireworms.

How To Prevent Wireworm In Tomato Plants?

Prevention is the best line of defence against wireworms, mainly if you have encountered wireworm infestation. Practice crop rotation, till the soil, and remove the debris to prevent future wireworm attacks on tomato plants.

Method 1 – Rotate Your Tomato Crops

It is essential to change the location of tomato crops every year. Planting them in the same location every year may create an environment ideal for wireworms.

Crop rotation prevents the wireworms’ infestation of tomato plants.

Method 2 – Prepare The Garden area

After harvesting the tomatoes, remove the debris and destroy them. Take care to kill the grass and remove the weeds.

Also, till the soil before planting to remove future attacks. I prefer to use a rotary tiller or hand tool to cultivate the soil.

Method 3 – Improve drainage

Wireworms prefer moist soil with poor drainage. So, improve the drainage properties of the soil to prevent wireworms from settling in your garden.

What Causes Wireworm Attacks In Tomato Plants?

The proliferation of wireworms is favoured by loose and sandy soils. Also, wet soils and poorly drained soils encourage more wireworm populations.

 Few vegetables, including carrots and potatoes, may help increase the wireworm population. So, avoid planting them near tomato plants.

Frequently Asked Questions

What are the preferred host plants of wireworms?

The most preferred host plants for wireworms are grasses. They feed on cultivated grass, sweet corn, ornamental corn, and potatoes. They also bore beans, beets, cabbage, carrots, cucumbers, lettuce, tomatoes, muskmelons, watermelon, radishes, peas, parsnips, and flowers.

Can diatomaceous earth powder be used to control wireworms?

Few gardeners have suggested the use of diatomaceous earth powder around the base of the tomato plants to deter wireworms. However, a research study showed that it did not interfere with the wireworm movement toward the bait. Also, it did not affect the mortality of these wireworms.

Can you use coffee grounds to prevent wireworms?

Few gardeners have suggested the use of diatomaceous earth powder around the base of the tomato plants to deter wireworms. However, a research study showed that it did not interfere with the wireworm movement toward the bait. Also, it did not affect the mortality of these wireworms.

In the end..

I hope this guide has helped you understand the different control measures for wireworms in your tomato garden. You may try one suitable for your needs.

Also, I am interested to hear about your experiences in dealing with these larvae.

Do share this guide with your friends and family to help them out too!