Protecting Your Yard

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Your backyard may be your sanctuary, but it may also be home to black-legged ticks, the tiny pests that can transmit the Lyme disease bacteria and other pathogens to you. Ticks can bite you while you’re gardening or relaxing in your yard, and they can bite your children or pets while they’re playing outside.

Repellents and tick checks are the cornerstones of tick bite prevention (for more information, see Preventing Tick Bites). But limited research suggests that modifications to your yard may reduce the number of ticks in your vicinity and, in turn, may lower your chances of coming into contact with a tick. As we explore each option, consider the costs, risks, and benefits of each to determine what protection measures make the most sense for your yard.

To help reduce the number of ticks in your yard, you want to create an environment that is not attractive to ticks or to their animal hosts, which include small animals such as mice, shrews, chipmunks, and birds, and larger creatures like deer.

Ticks use these hosts as transportation, hitching a ride when these animals move around the neighborhood. But hosts can also be a source of infection — ticks can pick up Lyme disease bacteria and other pathogens while feeding on these animals.

The two main ways to make your yard less attractive to ticks and their animal hosts are:

• Landscaping

• Treatments

Ticks prefer moist, shady areas such as

• woods

• stone walls

• leaf piles

• brush

• tall grasses

You can help keep ticks — and their animal hosts — out of these areas by creating a “tick-safe zone.” Take the following steps in areas of your yard that you and your family use most frequently:

• Keep grass mowed.

• Clear brush and weeds.

• Trim bushes and trees to allow as much sunlight as possible.

• Rake leaves.

• Reduce vegetation, particularly ground cover like the Japanese barberry shrub and pachysandra, where ticks like to live.

• Stack wood neatly in a dry, sunny space.

• Remove brush and leaves from around stone walls, and seal stone walls.

• Keep play areas, including swing sets and sand boxes, away from woods, leaf piles, stone walls, tall grasses, and shady areas.

• Reduce vegetation and leaf litter around decks and patios, and trim nearby trees to allow more sunlight on these areas.

• Create a three-foot-wide barrier of dry or less water-demanding material like wood chips, gravel, or mulch between your lawn and the woods, or around patios or play equipment.

• Keep bird feeders away from the house.

• Consider fencing to keep deer out.

• Keep trash cans well-sealed or in enclosed spaces.

Evidence shows that many of these steps, like removing leaf litter and reducing vegetation, can help reduce the number of ticks in your yard. While evidence is weak for creating a three-foot-wide barrier and keeping bird feeders away from the house, these relatively low-effort measures could make your yard a little safer.

Pesticides that kill ticks are called acaricides. In addition to landscaping measures, using acaricides may help reduce the number of ticks in your yard. There are two main ways to use them:

• treating lawn and vegetation

• treating tick animal hosts

Spraying acaricides on your lawn and vegetation can reduce the number of ticks in your yard. However, while reducing the number of ticks in your yard may reduce the likelihood that you’ll encounter a tick, it only takes one tick bite to get Lyme disease. That’s why repellents, tick checks, and other personal protection measures remain necessary, even if you have sprayed for ticks.

Several factors can affect how well treatment works, including:

• Type of spray used: some sprays are more effective than others.

• Pressure and coverage of the spray: the bigger the sprayer, and the greater the pressure, the greater the application.

• Timing of the spray: It’s best to spray once in spring and once in fall. Some organic products may require more frequent applications.

• Weather: Spraying during windy or rainy weather could reduce coverage.

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Studies done in residential settings show that highly controlled application of sprays can reduce the number of ticks in your yard for six to eight weeks, particularly when combined with landscaping measures.

However, additional research has shown that while neighborhood-scale treatments reduced tick numbers, this did not translate to reduced incidence of tick-borne diseases in humans. (There was, however, a significantly reduced incidence of tick-borne diseases in pets).

How should I spray my yard?

You can spray your yard yourself, or you can hire a licensed professional lawn treatment or pest control company to spray your yard for you.

In general, the larger the sprayer, the better the pressure and coverage of the spray. Target your lawn, woodland edges, and the areas around places that ticks like to live (such as brush, vegetation, and stone walls). You can also spray around the perimeter of areas where you and your family spend time, like patios, gardens, and playscapes. Do not spray plants that you intend to eat.

What type of spray should I use?

Make sure you pick an acaricide that specifically targets black-legged ticks. Some only kill dog ticks, which don’t transmit the Lyme disease bacteria.

Acaricides are available in several forms, including premixed sprays, concentrates that must be mixed with a liquid before spraying, and dry granules that may be spread around the yard. Both liquid and granule acaricides registered by the EPA have been shown to be effective at killing ticks, but liquid formulations tend to work a little better.

A group of acaricides known as pyrethroid acaricides are among the safest and most effective and are commonly used for tick control, but other types are also available. The EPA maintains a list of registered acaricides. Choose an acaricide that is both EPA-registered and registered with your state pesticide agency for use in your state.

If you use a lawn treatment or pest control company, they should be able to tell you which products can be used in your area. If you are spraying acaricides yourself, check with your town or city hall to see which products are allowed in your area. Always follow directions on the label for handling and application.

For more information on choosing a type of spray or a lawn treatment or pest control company, see the EPA Citizen’s Guide to Pest Control and Pesticide Safety.

If I don’t want to spray chemicals in my yard, are there other options?

Essential oil components derived from heartwood of yellow cedar, and certain fungi, are used as acaricides. However, they break down faster than chemical sprays, so they are not as effective and do not last as long.

When should I spray my yard for ticks?

Ticks that bite humans are mostly out in spring, summer, and fall, though you can get a tick bite any time the temperature is above freezing. A single application of spray in May or early June, when tiny nymph ticks are out, is the most important time to spray. You can then spray again in fall to help combat adult ticks. Check the product label or check with your lawn or pest control company to see if more frequent application is recommended.

Are tick sprays safe?

Pesticides registered by the EPA, when used according to package directions, are unlikely to cause serious health problems in children and pregnant women. When used properly, they are also generally safe for the environment. Check the acaricide label, or speak with your lawn treatment or pest control company, for specific safety information about the product you choose. Children and pets should stay off newly-treated areas until the spray dries (usually 12 to 24 hours).

All acaricide product labels indicate toxicity level as determined by the EPA:

• Danger-poison: highly toxic or poisonous if swallowed or if it gets on your skin

• Danger: highly toxic, and may include severe skin or eye irritants

• Warning: moderately toxic or hazardous

• Caution: slightly toxic or hazardous

• No signal word: practically nontoxic

For more safety information, see the EPA Citizen’s Guide to Pest Control and Pesticide Safety.

Instead of directly treating your yard for ticks, another option is to use a method that kills ticks on the animals that host them.

Tick tubes

One of the most common animal hosts of black-legged ticks, and of Lyme disease, are white-footed mice. Ticks can pick up the Lyme disease bacteria when feeding on a white-footed mouse, and then pass the bacteria on to you. If white-footed mice are abundant in your area, you can reduce your risk by exposing the mice to permethrin, a pesticide that kills ticks.

You can do this using tick tubes. These are long tubes filled with permethrin-soaked cotton that you lay around the perimeter of your yard. Mice will take the cotton and use it to build their nests. The permethrin then kills ticks that try to feed on the mice. You can buy tick tubes at hardware or home and garden stores.

Research on the effectiveness of tick tubes has shown mixed results. In some studies, the approach did a good job reducing the number of ticks. In other studies, it was not very successful. Factors such as geographic location and timing of tick tube placement may explain the difference in outcomes, but more research is needed.

For more detailed information on protecting your yard from ticks, refer to the Connecticut Agricultural Experiment Station’s Tick Management Handbook, which is recommended by the CDC.