Wireworms are a common and destructive garden pest that can be very difficult to control. The larvae of click beetles, wireworms feed on the roots of vegetables, potatoes, strawberries and ornamental plants, damaging and even killing the plants. While there are no quick fixes, there are some effective strategies to help reduce wireworm problems in the garden.
Prevent Wireworms Before Planting
Taking some preventative measures before planting is the best way to avoid issues with wireworms in the first place. Here are some tips:
Choose Resistant Varieties
When possible, opt for wireworm-resistant vegetable varieties. Some options include:
- Potatoes – Russet Burbank, Shepody
- Carrots – Danvers, Scarlet Nantes
- Onions – Southport White Globe
Rotate Crops
Avoid planting in areas of your garden where root crops or grasses grew the previous year. Rotate between crop families each season.
Remove Grass and Weeds
Eliminate grasses and weeds around garden beds, as they can harbor wireworms. Cover the area with black plastic for a few weeks before planting to kill pests.
Incorporate Organic Matter
Work aged manure, compost and other organic matter into the soil to improve conditions for plant growth so they can better withstand pest damage.
Delay Planting
Plant crops later in the spring after the soil has warmed thoroughly, giving wireworms less time to inflict damage before harvest.
Control Wireworms After Planting
If wireworms are already present, there are several approaches to limiting further damage:
Hand Pick Wireworms
Check beneath mulch and dig around damaged plants to find and remove any visible wireworms. Look for slender, copper-colored worms that may curl up when disturbed.
Use traps
Bury shallow containers of grain, carrots or potato slices 3-4 inches into infested garden beds. The bait will attract wireworms overnight, and you can dispose of them in the morning. Re-bait the traps continually to catch newly emerging larvae.
Apply Beneficial Nematodes
Nematodes are tiny worm-like organisms that parasitize insect pests. Steinernema feltiae is a species proven effective against wireworms. Apply nematodes per package instructions.
Encourage Natural Predators
Ground beetles and birds feed on wireworms. Avoid pesticides that may kill beneficial predators, and use mulch to create habitat for them.
Protect Plants with Row Covers
Covering planted rows with fabric row covers can create a physical barrier to keep wireworms from reaching crop roots.
Use Repellent Plants as Companions
Planting onions, garlic, marigolds or tansy near crops can help deter wireworms with their strong scents.
Apply Insecticides Sparingly
Insecticide baits can temporarily reduce wireworm damage but also kill helpful insects. Use only as a last resort.
Control Wireworms with Good Garden Care
Along with targeted wireworm treatments, maintaining good overall garden health can help reduce pest problems.
Loosen and Aerate Soil
Use a tiller or digging fork to gently loosen and aerate soil prior to planting, which improves root growth.
Add Organic Mulch
A 2-4 inch layer of shredded leaves, straw, or other organic mulch helps conserve moisture, adds nutrients and keeps soil cooler.
Water Infested Areas
Ensure crops receive 1-2 inches of water weekly, as wireworms thrive in hot and dry conditions. Moisture allows plants to recover from pest damage.
Rotate Mulch Annually
Remove and replace organic mulches in garden beds each year to prevent wireworms from accumulating.
Clean Up Thoroughly
In fall, remove all garden debris, plant residues and remaining roots after harvest to eliminate overwintering sites.
Common Wireworm Control Questions
Do wireworms come back every year?
Yes, wireworm adults can live for several years, continually reproducing and laying eggs that become new larvae each season. Their populations build up over successive years if preventive steps aren’t taken.
When is the best time to apply beneficial nematodes?
Apply nematodes about 2-4 weeks before planting or soon after seeing wireworm damage. Avoid hot weather above 90°F. Water treated areas thoroughly before and after application.
How long does it take diatomaceous earth to kill wireworms?
Diatomaceous earth can take 1-2 weeks to kill wireworms. It must come into direct contact with the insects and be reapplied after rain or irrigation. It’s more effective against young larvae.
What home remedy kills wireworms instantly?
There are no instant home remedies, but insecticidal soaps, neem oil and spinosad concentrates can provide fairly rapid wireworm control when applied as drenches at the first sign of damage.
Conclusion
While wireworms can be persistent garden pests, taking preventative measures before planting and promptly addressing any damage can help limit their impact. Rotation between beds, removing habitat, hand picking, traps, and applying biological controls are strategies that can reduce wireworm problems without the use of harsh pesticides. Along with vigilant monitoring and quick treatment of infestations, nurturing overall garden health also helps deter wireworms for good crop yields.