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When we think of garden pests, we often consider only those insects that damage or kill our plants. But what about pests that target the gardener? Last year, my lawn and flowerbeds were inundated with fleas. While we often think of fleas as a pet issue, these bloodthirsty bugs have no problem snacking on an unwary gardener like myself. That's when I discovered the benefits of biological flea control.

Fleas in the Grass

How did I get so many fleas in my yard? It's simple. From coyotes and foxes to feral cats and stray dogs, a number of flea-harboring animals cross my backyard each day. The fleas these animals carry produce smooth, oval eggs which easily slip out from the host animal's coat.

As the eggs sink into the lawn or garden, the humidity and shade from plants create the perfect environment for hatching. Flea larvae feed upon organic debris. Like many gardeners, I have no shortage of rich and nutritious organic material in my yard. 

After feeding, fleas pupate inside silk cocoons before emerging as adults. Their entire life cycle can take as few as two to three weeks. Since these pests were living where I wanted to weed and tend my plants, I needed a safe and effective method to kill fleas in yard and garden areas. And I needed it fast!

Controlling Fleas with Nematodes

That's when I engaged the help of parasitic bugs. Sometimes referred to as roundworms, nematodes are microscopic unsegmented worms. Beneficial nematodes seek out a specific insect host to parasitize. One species of roundworm, Steinernema carpocapsae, targets and kills various life stages of fleas.

As gardeners, you might be familiar with the damage caused by root knot nematodes. Rest assured, beneficial nematodes are different than those which attack plants in the garden. Using beneficial nematodes to kill fleas in the yard and garden is completely safe for humans, pets, wildlife, plants and even vegetable garden crops.

More importantly, I've found Steinernema carpocapsae to be quite effective at reducing the flea population in my yard. They begin killing fleas within 48 hours and will remain in the soil as long as six weeks after the fleas have been eradicated. 

How to Kill Fleas with Nematodes

I've only found one downside to using beneficial nematodes. As a biological control method, these are living creatures. They require special handling and the application instructions need to be followed precisely. Here are a few guidelines to consider before purchasing flea-destroying nematodes:

  • Keep the area moist - Nematodes are quite susceptible to dehydration. I thoroughly watered the area before and after application, then on days when it didn't rain for the next week.
  • Application time - I chose to apply the nematodes in the evening on a cloudy day. This gives these microscopic worms the most time to filter down to the soil surface.
  • Proper handling - As instructed, I placed the pouch containing the nematodes in the refrigerator as soon as it arrived and applied them to the yard within the recommended two week period.

For me, this biological control method was the best way to kill fleas in the yard. Within days of applying nematodes, I could safely work in my garden again. No more flea bites and definitely no worries about harmful side effects.

Laura Miller

Laura Miller has been gardening all her life. Holding a degree in Biology, Nutrition, and Agriculture, Laura's area of expertise is vegetables, herbs, and all things edible. She lives in Ohio.