Mothballs

For generations, mothballs have been celebrated as a way to keep rodents, snakes, and insect pests out of the garden.

Don’t do it.

Mothballs (Public Domain)

Popular claims about mothballs in the garden

In one article, you are urged to add a few mothballs to a potted plant and then cover the whole thing with a plastic bag for a week as a sure-fire way to get rid of insect pests. In another post, you are told that adding mothballs to the garden will repel mice and rats. Then a friend urges you to scatter mothballs throughout your garden to deter squirrels, snakes, and rabbits. Is any of this a good idea?

No, it isn’t.

What are mothballs, anyway?

You might remember smelling mothballs in your grandmother’s closet, attic, or basement. That distinct scent is unmistakable. Mothballs are spheres or disks of pungent chemicals that slowly evaporate into a gas that is toxic to moths and moth larvae. This is why people have used them to protect clothing and other fabric materials while in storage. 

The chemicals used to make mothballs can be naphthalene or paradichlorobenzene, both of which are carcinogenic neurotoxins that have no business near your food. There are clear and important instructions on how to use mothballs properly, if you must. For one thing, containers must be completely sealed to prevent long term exposure and the associated health risks.

The truth is, it is illegal to use mothballs as a pesticide in many states. According to the National Pesticide Information Center, using mothballs outside poses a risk to children, pets, and local wildlife. Mothballs can also contaminate soil and water. 

So, the next time someone suggests using mothballs in the garden, you can protect them by educating them.