With the news filled with stories about Rocky Mountain spotted fever, Lyme disease and other problems caused by the many species of ticks that abound in the world, it's important to consider ways to control these tiny parasites. The CDC notes at least 15 different diseases that can potentially be carried by these insects. While you can't control ticks in the wild, there are steps you can take to minimize their presence in your own landscape. The general goal is to keep ticks from coming into your yard by restricting animals that carry ticks (such as deer) or by applying pesticides along the yard perimeter. You can also make your landscape less tick-friendly so the insects are not encouraged to thrive.
The Biology of Ticks
Ticks are parasitic members of the arachnid class of animals—the same animal family that includes spiders and mites. Of the 800 or so different species found worldwide, only two families of ticks, Ixodidae (hard ticks) and Argasidae (soft ticks), are known to transmit diseases to humans. The vast majority of tick bites do not lead to illness. But because these animals must feed on blood in order to complete their life cycle, when a tick that carries disease-causing microbes does bite, the chances for transmitting the microbe is very real.
It's specifically the black-legged tick (Ixodes scapularis) that can transmit Lyme disease, so if you live within its range (Eastern North America into the upper Midwest), this type will be your biggest worry. Ixodes scapularis can be transported into your landscape by deer or other hooved mammals, such as moose. Deer are such a common host that the parasites are commonly called "deer ticks."
If you live in a region where any of these known diseases are common, it makes sense to take efforts to keep the ticks that carry them out of your yard before resorting to the use of chemicals to kill them. The chemicals that kill ticks are known to also kill beneficial spiders and other animals, so prevention should be your first effort
If you're gearing your efforts specifically to the control of deer ticks to minimize risks of contracting Lyme disease, one of your objectives should be to keep deer and similar animals away from your landscape, lest they bring Ixodes scapularis with them. There are three common ways to achieve this goal:
More generally speaking, experts recommend creating an environment in your landscape in which ticks are less likely to survive. Ticks need two things for survival: humidity and a host upon which to feed (in addition to deer, common hosts are pets, rodents, and birds).
To the degree that you can eliminate or minimize those two things, you can also reduce the probability of a tick infestation. Certain changes in landscaping practice can also help. For example, you can modify your yard so that you won't be regularly brushing up against shrubs when walking along pathways. Dense groundcovers can also harbor ticks. A neat, tidy yard with dry conditions and no wildlife holds no appeal for ticks.
Killing Ticks With Spray Pesticide
Deterring or killing ticks with pesticide should be a last resort for homeowners, due to the inherent risks of chemical use. Although there are so-called "organic" pest controls, few of these are very effective against ticks. And even organic pesticides have some environmental impact. They may, for example, be so much less effective than synthetics that they require many more applications. Organic treatments also can be much more expensive than many synthetic chemical pesticides.
When to Spray for Ticks
The best time of year to spray is when the ticks are in their early nymphal stage. For deer ticks, this means spraying in May or early June.
- Working Time: About 2 hours to mix solution spray a medium-size yard
- Total Time: About 2 hours
- Material Cost: One quart of concentrated synthetic chemical tick killer costs $25 and will make enough solution to cover a large yard. A 32-oz. container of organic tick killer costs about $35 and will cover about 5,000 square feet, but it may require repeated applications.
What You'll Need
- Garden sprayer with hose attachment
- Protective clothing (long pants and shirt, breathing protection)
- Organic or chemical pesticide
Choose a Pesticide
You have two options when spraying for ticks: organic controls or a synthetic chemical acaricide.
Organic controls: The Center for Disease Control (CDC), in an article titled "Natural Tick Repellents and Pesticides," recommends biological agent-based products that contain a fungus (Metarhizium brunneum/anisopliae) as the active ingredient. Specifically, the CDC states that these products are EPA-registered and commercially available and that they kill black-legged ticks and are intended for use on lawns and gardens. Consider Met 52 EC which comes in an 8-ounce bottle.
Synthetic chemical acaricides: If you are not committed to staying natural, you'll likely be considering chemical treatments for ticks. These are often categorized as acaricides, a group of pesticides that target ticks, mites, and other closely related invertebrates. One such product that kills ticks (and many other bugs) is Onslaught FastCap Spider & Scorpion Insecticide. With active ingredients including Esfenvalerate, Prallethrin, and piperonyl butoxide, it works by disrupting a pest's nervous system.
Acaricides come in three forms:
- An RTU product (ready to use; attaches to a garden hose)
- An RTS product (ready to spray; comes in a pump bottle)
- A spray that you mix yourself (apply with your own pressurized sprayer)
The chemicals tend to be similar in these products, so the choice will depend on your preference. Chemicals you mix yourself and apply with your own garden sprayer have some built-in risk of contact with chemicals as you pour and mix, but this can be by far the least expensive form. Ready-to-spray chemicals are somewhat expensive, but they eliminate the need to mix chemicals by hand. Ready-to-use products that attach to a hose are best for spraying very large areas.
Plan Your Attack
The correct place to apply an acaricide is along border areas, where a potential tick habitat (woods, brush, etc.) meets your lawn. Spray several feet into both sides of such a border (that is, into both the woods side and the lawn side). This practice is termed "perimeter spraying."
Apply the Spray
There are different ways to spray for ticks. Before deciding to do it yourself, you are well advised to consider calling in a pro. Professionals will have more powerful spraying equipment, allowing for better penetration of the acaricide, and they know how to safely handle the chemicals. If you choose to apply the spray yourself:
- Attach the hose sprayer or mix up an acaricide solution in a garden sprayer. Make sure to carefully follow label directions.
- While wearing long sleeves and trousers and wearing breathing protection, apply the spray all over the potential tick habitat. Pay particular attention to border areas between lawn and wooded or shrubby areas.
It's generally sufficient to spray once in late spring, as the feeding and reproduction season for ticks is relatively short. By mid-summer, the ticks are unlikely to be much of a problem.
Any pesticide comes with one enormous liability— it will kill other creatures in addition to the targeted pest. If you apply a truly effective targeted acaricide that kills ticks, for example, you will almost certainly also kill helpful spiders that may be feeding on noxious insects, such as mosquitoes. And any birds that might be eating ticks and other spiders will then be denied one of its food sources.
If you are applying a more broad-spectrum pesticide, you may well be killing a great many beneficial insects, such as honeybees, ladybugs, and mantises. Responsible gardeners need to think long and hard about using such chemicals.
If you are environmentally conscious, first try organic methods combined with landscape modifications. If you do apply synthetic chemicals, limit the application area to border areas surrounding your yard, and avoid widespread broadcasting of these chemicals across your entire lawn and yard.
Human health hazards should also be considered. Be very careful when mixing chemicals, and wear protective breathing masks when applying so you don't breathe in the chemically laden mists. Manufacturers of pesticides may downplay human health hazards, but it is best to treat all such products as extremely toxic. Some pesticides once regarded as safe (such as DDT) have later been determined to be quite poisonous.
Tips for Preventing Ticks
The CDC offers this list of preventive measures to discourage ticks from your yard:
- Remove leaf litter.
- Clear tall grasses and brush around homes and at the edge of lawns.
- Place a 3-foot wide barrier of wood chips or gravel between lawns and wooded areas to restrict tick migration into recreational areas.
- Mow the lawn frequently.
- Stack wood neatly and in a dry area (which discourages rodents).
- Keep playground equipment, decks, and patios away from yard edges and trees.
- Discourage unwelcome animals (such as deer, raccoons, and stray dogs) from entering your yard by constructing fences.
- Remove old furniture, mattresses, or trash from the yard that may give ticks a place to hide.