Mothballs in the garden

Don’t use mothballs in the garden

For many years I have worked to discourage people from using “mothballs” to repel animals from their homes and gardens.   I am now seeing articles on line encouraging people to use them in the garden for all sorts of things from deterring Japanese beetles to scaring away squirrels.  Mothballs are about the farthest thing imaginable from a safe, natural way to repel pests.  I personally wouldn’t use them in the house even to discourage clothes moths.

Mothballs contain one of two ( sometimes both) highly toxic chemicals, naphthalene and Para dichlorobenzene.  These chemicals are classified as hazardous and a possible carcinogen by the EPA.   There are sometimes other hazardous chemicals in mothballs too. Pesticides, which mothballs are, (they are not a repellant, they kill insects), are labeled as to how to use the product and by law they cannot be used any other way.

Mothball boxes, if you read them, do not list the use of the product outdoors, or to repel animals. So if you use them in this way you are breaking the law. If you instruct people to use them in a non-approved way you are also breaking the law.

But breaking the law is not the most important consideration. These chemicals do serious damage to humans and other animals exposed to them. They can be absorbed through the skin, inhaled, or ingested. The amount of damage done varies as to exposure and who is exposed, but severe and fatal consequences can occur.

The chemicals in mothballs can cause hemolytic anemia, damage to the liver and kidneys, neurological damage, cataracts and damage to the retina. Children, pets, people who already have liver or kidney problems or some forms of inherited blood disorders are at special risk. Deaths have occurred from naphthalene and Para dichlorobenzene exposure in both children and adults.

Using a lot of mothballs in an attic or crawl space may allow toxic fumes to enter the living area and just breathing those fumes can be hazardous. When people place mothballs outside in an attempt to discourage animals they are exposing themselves, children and pets to possibly fatal reactions. The chemicals also pass through the placental barrier and a pregnant woman who handles mothballs or even exposes herself to the fumes for an extended period of time can damage her baby.

Soil that is contaminated with dissolved mothballs is also toxic; plants should never be consumed if they are grown in soil contaminated by mothballs. It’s not known how long the contamination remains in the soil.

If you can smell the mothballs you are inhaling vaporized poison. If a child or pet swallows just one mothball it can cause serious problems and the poison hotline should be called immediately. (1-800-222-1222).  The pesticides in mothballs can be absorbed through the skin by children handling them or pets walking on them.  Never put them in pet’s beds or store them with pet food.  Don’t use them in any food area.

Mothballs are a toxic pesticide and should be treated as such.  They are definitely not an organic or safe solution to garden or pest problems.  They are intended to be used in an enclosed area to prevent insects from eating stored clothing. Read the label on the box and follow it.  Even though your grandmother used them all over the house doesn’t mean they are safe. Your grandparents also used DDT without knowing the consequences. And the old wives tale of discouraging animals with mothballs doesn’t work most of the time anyway.

Here’s national pesticide hotline page on toxic effects of mothballs.


  1. I threw mothballs under my house to get rid of a bunch of skunks that were underneath my house chewing and clawing their way to the hot water pipes under my bathroom one winter. They would get into fights and spray and the stink would fill my house! Boy was this a bad move on my part. The fumes from the mothballs filled my house just as the stink from the skunks had. It made me stop and think about what a terrible thing I had done without thinking it through. I felt awful for doing it to an animal just trying to survive the winter.

    1. One hour ago before I read this, I had but cut off pantyhose legs filled with mothballs tied around my mango tree trunk and branches.
      I wish I had read this first. I am now going out there to remove them. thank you for the information.

  2. The chemicals in mothballs are not translocated into edible plants