Natural Ways to Treat and Kill Fleas in Grass

By PetMD Editorial on Apr. 8, 2016

By Aly Semigran

Whether your pet is going outside to play or just relax, your backyard is likely a place your four-legged companion frequents and enjoys. However, fleas may be hiding in your yard and can latch onto dogs (or cats) while they are rolling around in or even just walking through the grass during the spring, summer and fall months.

Luckily, there are safe solutions provided by veterinarians and natural lawn care experts for pet parents who want to rid their grass of fleas in a natural, non-toxic way.

Fleas Thrive in Warm Weather 

While fleas can be found on your cat or dog year-round, they tend to cause more issues during the spring, summer and fall. This can be due to the warmer climates and fleas’ breeding habits. “Fleas develop in protected microhabitats such as crawl spaces under structures, vegetation next to the house, pet bedding, dog houses, and places that create high humidities,” explains Dr. Michael K. Rust, Ph.D. of the University of California, Riverside.

Phil Catron the President of NaturaLawn of America, adds that fleas are very active “between the temperature range of 70-85 degrees, coupled with 70+ percent humidity,” which explains why the pest battle heats up during warmer months. 

But keep in mind—fleas don’t disappear when the temperature drops. Flea pupae in their cocoons can stay dormant for up to a year in lower temperatures.

Prepping Your Yard to Keep Fleas Away

Catron says that the first line of defense for keeping fleas out of your grass is to maintain a clean yard. “Flea larvae don’t like light and adult fleas will lay eggs beneath all kinds of debris, including leaves and furniture,” he says. “They like cool dark places and removing these makes your yard less appealing to them.”

In addition to raking leaves and removing any furniture that is not being used, Catron suggests removing wood and dirt piles, which are ideal flea hiding spots. “Cleaning up the flea havens in your yard not only makes them more likely to find somewhere safer to hide, it exposes the fleas to whatever treatment you choose, which makes your efforts to eradicate them more effective,” he says.

Natural Remedies to Kill Fleas in Your Yard

If fleas have still managed to pop up in your cleaned and maintained yard, there are natural ways to deal with the problem. 

Diatomaceous Earth

“One of the best natural materials which may be used to control fleas outside is diatomaceous earth, often simply referred to as DE,” Catron explains. “DE is the remains of millions of fossilized simple cell organisms which are left over from dried up water sources.”

DE can be applied by spreading the dry powder around the lawn. But, Catron suggests another method. “Mixing DE with water is the easiest and least messy way,” he says. “Using roughly ¼ to ½ lb. of DE and mixing it with water in a sprayer is enough to treat up to 1,000 square feet of lawn. Because the DE powder is not soluble in water, consistent agitation is necessary so the particles stay suspended as much as possible.”


Glen Baisley of Neave Group Outdoor Solutions, notes that another effective and safe solution is the use of nematodes, which are microscopic roundworms that kill pests and other insects. Not only will they not harm your pets, but they are “available at most garden centers.”

“Nematodes typically come packaged and impregnated onto a flexible material,” Catron explains. “The piece of material contains millions of these tiny microscopic worms and when placed into a water solution will be dispersed from the cloth-like material and end up in the spray solution.”

The nematode water solution is then sprayed on to the lawn that needs the treatment. “The recommended rates will vary with the type of nematode and how much of a population of nematodes is impregnated onto the material,” he notes.

But there’s things to keep in mind when it comes to applying the nematodes. “Since they are living organisms, they need to breathe too so only mix up what you will be spraying within a reasonably short period of time. If left in a spray tank for too long (say several hours) they will actually drown and be of no use,” Catron says. He notes that nematodes are also “sensitive to light and heat and drought so the best time of the day to treat with nematodes is in the early morning, evening or on a cloudy day.”

So how do they work exactly? Catron explains that the nematodes will “enter the flea’s body through any opening it can find. Once inside it will release a bacteria which kills the flea (usually within 24-48 hours). Once the flea is dead, the nematode will begin to reproduce itself inside the dead carcass. This results in the release of more parasitic nematodes into the surrounding area and helps in the overall control.”

Homeopathic and holistic vet Dr. Stephen Blake, DVM, CVA, CVH, uses a combination of nematodes and dish soap when it comes to dealing with fleas.

“Put two ounces of dish soap in an Ortho hose sprayer bottle and fill the rest up with water. Spray the entire yard once or twice per week to kill adult fleas,” explains Blake. “Repeat as needed or weekly for prevention during flea season. Do not spray succulent plants or, if you do, rinse them off after spraying them.”

What To Avoid When Controlling Fleas In Your Yard

Whether you opt for a natural treatment for fleas or go with a chemical alternative, it’s important to know what’s safe to use around your pets. Before treating your yard, make sure to discuss the potential dangers with your veterinarian.

“Many of the pesticides on the market used for flea control contain organophosphates, and this class of chemicals is a nerve poison,” Catron warns. “Overexposure can cause skin irritation on pets and also affect the cholinesterase levels in their blood leading to serious sickness.”

It’s also important to be aware of other types of synthetic materials which may contain pyrethroids, which can affect the skin and respiratory systems of pets and humans alike, Catron adds.

And while you’re talking to your veterinarian about safe yard treatment options, make sure you also ask about appropriate flea preventatives for your pet. Treating all the animals in your home as well as their environment is the best way to get rid of fleas.

Image:  via Shutterstock

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