Wireworms in strawberries - Ask Extension
I removed old plants from a small raised bed . It had strawberries prior. Should I remove the soil? I wanted to replace with new strawberries but I do...
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Wireworms in strawberries #925854
Asked March 11, 2026, 2:10 PM EDT
I removed old plants from a small raised bed . It had strawberries prior. Should I remove the soil? I wanted to replace with new strawberries but I dont want the wire worms to return .my soil and entire raised bed is organic. Thanks.
Lane County Oregon
Expert Response
Adults and larvae both overwinter in soil, anywhere from 6-24 inches (15-61 cm) deep. When soil temperatures reach 50-55 degrees Fahrenheit (10-13°C) adults emerge, mate, and lay eggs in the soil. At this point larvae move within about 3 inches (8 cm) of the soil surface to feed. As the season progresses and soil temperatures increase to 80 degrees Fahrenheit (27°C) and above, larvae move deeper in the soil, where they will typically remain until the next spring. Wireworms generally take anywhere from two to six years to mature, but eventually larvae pupate within the soil and emerge as adults.
Bait trapping:
Bait traps should be set before soil temperatures reach 50 degrees Fahrenheit (10°C) at a 4-inch depth, preferably a month before planting (Figure To monitor using this method:
Soak untreated cereal or corn seed in water for 24 hours Place about 1/2 cup of seed in a hole about 3-5 inches deep and bury, but do not pack soil Lay a piece of black plastic (approximately 1-3 ft square) over the trap location and cover plastic with soil to keep it in place (optional, but this should increase soil temperature and encourage wireworm activity)Flag or otherwise mark trap. Retrieve traps in 7-14 days Look through bait (soaked seed) and soil immediately surrounding it for wireworms. Drying the top 15 inches of soil can target eggs and larvae of Pacific coast wireworm (Limonius spp.)
Cultivation of the ground can briefly expose the grubs to predators, such as birds
Encourage predators and other natural enemies in the garden such as birds, wasps, and ground beetles
Remove larvae of wireworms from soil as they are found .
The nematode Heterorhabditis bacteriophora is sold as a control for wireworm. To be effective the nematodes need to be watered into moist soil while soil temperatures are in the range of 12-20ºC (54-68ºF). These temperatures occur between April and September. Nematodes should be applied as soon as possible after purchase, following the suppliers’ instructions. It may be necessary to water the soil before and after application to ensure the soil is sufficiently moist for nematode activity and survival. Repeat application may be necessary. The nematodes may also affect other insects in the soil and so should be used in a targeted manner.
Bait trapping:
Bait traps should be set before soil temperatures reach 50 degrees Fahrenheit (10°C) at a 4-inch depth, preferably a month before planting (Figure To monitor using this method:
Soak untreated cereal or corn seed in water for 24 hours Place about 1/2 cup of seed in a hole about 3-5 inches deep and bury, but do not pack soil Lay a piece of black plastic (approximately 1-3 ft square) over the trap location and cover plastic with soil to keep it in place (optional, but this should increase soil temperature and encourage wireworm activity)Flag or otherwise mark trap. Retrieve traps in 7-14 days Look through bait (soaked seed) and soil immediately surrounding it for wireworms. Drying the top 15 inches of soil can target eggs and larvae of Pacific coast wireworm (Limonius spp.)
Cultivation of the ground can briefly expose the grubs to predators, such as birds
Encourage predators and other natural enemies in the garden such as birds, wasps, and ground beetles
Remove larvae of wireworms from soil as they are found .
The nematode Heterorhabditis bacteriophora is sold as a control for wireworm. To be effective the nematodes need to be watered into moist soil while soil temperatures are in the range of 12-20ºC (54-68ºF). These temperatures occur between April and September. Nematodes should be applied as soon as possible after purchase, following the suppliers’ instructions. It may be necessary to water the soil before and after application to ensure the soil is sufficiently moist for nematode activity and survival. Repeat application may be necessary. The nematodes may also affect other insects in the soil and so should be used in a targeted manner.
Would it be effective to remove the soil from this raised bed ?
Yes, that would be fine. Note the depth indications for then to do that.. Soil temp is important.
You are very welcome.
