Nematodes: The Natural Solution for Pest Control

Nematodes are microscopic, parasitic worms that naturally occur in soil. They are safe for plants, animals, and humans but deadly for many garden pests. These beneficial nematodes seek out and infect pest insects, killing them from the inside out. Why add chemicals to the earth to kill pests when you can have nematodes do the work?

Uses of Nematodes in Pest Control

Nematodes are effective against a wide range of garden pests including:

• Grubs, Cut Worms and Root Worms
• Weevils
• Cucumber Beetles, and other beetle larvae in the soil
• Western Flower Thrips
• Fungus Gnats and Shore Flies
• Fleas and much, much more!

Application Methods

Water is the carrier and nematodes are mixed into a solution before they are applied. Nematodes are typically applied to the soil, but at times directly to the plants. They can be watered into the soil or sprayed onto the foliage. The application timing may vary depending on the specific pest being targeted, but application tools include watering buckets, backpack sprayers, spray tanks and other irrigation equipment. 

Timing of Application

The best time to apply nematodes depends on the pest lifecycle. For example, to control grub worms, apply nematodes in late summer when the grubs are most active. For other pests, application may be more effective in the spring or fall. All nematode species have a specific temperature range when they are most active. Some need soil temperatures over 70°F (Hb, Sc) while others can infect pests in temperatures as low as 50°F (Sf). Timing and temperature are an important part of using this natural pest control.

Benefits Over Chemical Alternatives

Nematodes offer several benefits over chemical pesticides:

• Safe for pets, children, and wildlife
• Do not contaminate soil or water
• Target specific pests without harming beneficial insects
• Effective on over 200 soil dwelling pests
• Fast-acting, killing pests within 24-48 hours
• Can be used in combination with other natural methods
• Pests cannot develop resistance to nematodes as they do to chemicals
• Decompose naturally in the soil leaving no harmful residues
• Compatible with IPM programs and other biological control organisms
• Promotes a healthier and more sustainable environment

How to Use Nematodes

1. Choose the right nematode species for your specific pest problem. Review our Nematode Tech Sheet for this information. Nematodes have extremely long names that can be impossible to pronounce. Feel free to use and say the abbreviated form. 

• Steinernema feltiae - Sf
• Steinernema carpocapsae - Sc
• Heterorhabtitis bacteriophora - Hb

2. Apply at the correct time based on the pest lifecycle. We can help with this if you don't want to become an entomologist.

3. Follow application instructions for the best results. Learn How to Apply Nematodes here. 

4. Maintain moist soil to help nematodes move and infect pests effectively.

5. Combine with other natural methods, like mycoinsecticides or other beneficial insects and mites for comprehensive garden protection.

Case Studies

Jeremy works in a greenhouse and notices fungus gnats have exceeded the damaging threshold and are covering the yellow sticky cards. Since temperature is consistently at 68°F year-round he chooses to apply Steinernema feltiae (Sf) every 2 weeks during the spring season through the irrigation equipment. Nematodes are never mixed with soluble fertilizer, but can be applied before or after fertilization. After a month or two he notices there are not nearly as many fungus gnats in the greenhouse so he changes to monthly applications to maintain control. 

Chelsea owns a flower farm and every year has a terrible time with Cucumber beetles on her Dahlias. She notices the adult cucumber beetles emerging from overwintering in the soil in mid April. She waits a few weeks when they are due to start laying their eggs and makes weekly nematode applications with 3-way nematode blend around the base of her crops to target the eggs and larvae of the beetle. After three weeks she switches to monthly applications during the remainder of the season to target the next generation of beetles. She applies organic pesticides for the adults and also used traps and lures to catch them and prevent reproduction. 

Alex works on a private estate. He notices notching and chewing on the edges of the extensive rhododendron hedge from black vine weevils. Since it's summertime and the temperatures are between 70 to 90°F he chooses Heterorhabditis bacteriophora (Hb) to target the larvae in the soil. He applies these entomopathogenic nematodes early in the morning in June and September while the larvae are actively feeding on the roots. He covers the base of the rhodies with tanglefoot to trap the adults before they can reach the leaves. 

Conclusion

Nematodes are a powerful tool in the fight against garden pests. By understanding what they are, how they work, and how to apply them effectively, you can create a balanced and thriving garden ecosystem without resorting to harmful chemicals. Let us know your experience with nematodes and share, The Power of the Worm!