Yes, cayenne pepper can help keep wildlife out of your garden

Cayenne pepper is a hot chile pepper typically used as a spice to add heat to a variety of dishes, like tacos, stir fry and curries.

But some people on social media claim cayenne pepper can also help keep squirrels, cats, rabbits and even insects out of their gardens.

VERIFY reader Dani asked if cayenne pepper actually works to repel wildlife.

THE QUESTION

Can cayenne pepper keep wildlife out of your garden?

THE SOURCES

• National Pesticide Information Center (NPIC), a cooperative agreement between the Environmental Protection Agency (EPA) and Oregon State University
• Cornell University
• North Carolina State University Extension
• University of Connecticut
• University of Massachusetts Amherst
• Wild Birds Unlimited Nature Shop in Eugene, Oregon
• Steve Reiners, Ph.D., professor and chair of the Horticulture Section in the School of Integrative Plant Science at Cornell University 
• Dana Sanchez, Ph.D., associate professor and extension wildlife specialist at Oregon State University
• Jon Traunfeld, extension specialist and director of the Home and Garden Information Center at the University of Maryland
• Roger Dickens, technical services manager at Terminix, a pest control company

THE ANSWER

Yes, cayenne pepper can keep wildlife out of your garden. However, it can also be harmful to some pollinating insects.

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WHAT WE FOUND

Our sources agree that cayenne pepper can keep wildlife, like squirrels, rabbits and rodents, out of your garden. Cayenne pepper can also be used to repel insects. However, it can be harmful to bees and other pollinators, so it’s important to use caution when applying it.

Capsaicin, the main chemical that makes cayenne peppers hot, is a temporary animal and insect repellent due to its strong odor and hot taste.

“Capsaicin is the compound in chile (cayenne) peppers that produces a burning sensation. It can repel mammals like squirrels and rabbits,” Jon Traunfeld, extension specialist and director of the Home and Garden Information Center at the University of Maryland, told VERIFY.

The National Pesticide Information Center (NPIC) says that most wildlife, except birds, will avoid capsaicin in backyards and gardens because it has such a strong odor and hot taste that some animals don’t like. Birds, on the other hand, cannot taste the chemical and will not be repelled by it.

“Scientists think peppers evolved to produce capsaicin to keep animals from eating the fruit,” Steve Reiners, Ph.D., a plant science professor at Cornell University, wrote in 2021.

Capsaicin is most concentrated inside chile peppers near the seeds, according to Reiners and Dan Gleason, owner of Wild Birds Unlimited Nature Shop in Eugene, Oregon.

“[Capsaicin] stimulates a certain kind of pain receptor found in mammals but not in birds, and that’s why birds have no adverse reaction to eating peppers,” Gleason said.

“In mammals, these pain receptors are found throughout the body, not just in the mouth, which is why it is recommended that you wear gloves when peeling and handling jalapeño peppers, for instance,” Gleason added.

In addition to deterring animals, the University of Connecticut says capsaicin is also used as an insect repellent. It can be used to control aphids, spider mites, thrips, whitefly, lace bugs, leafhoppers and other pests by damaging cell membranes and disrupting the nervous system, according to the university.

But it’s important to note that capsaicin is toxic to pollinators like bees and other beneficial insects, including some that reside in the soil, according to Dana Sanchez, Ph.D., associate professor and extension wildlife specialist at Oregon State University.

Scientists do not recommend applying products containing capsaicin to blooming crops or weeds if bees or other beneficial insects are visiting the treatment area.

Products containing capsaicin are usually sold as aerosols, liquids or in granular formulations, such as ground cayenne pepper. The NPIC says the use of these products can cause coughing and temporary blindness in animals, and can also prevent their vocal cords from working for a short time.

“Sprinkling cayenne powder or crushed chile flakes around the garden perimeter or around plants could give a critter a ‘hot foot’ or get into the mouth and cause discomfort during grooming,” said Traunfeld.

If you have a pet, like a cat or a dog, the NPIC says they may be exposed to capsaicin if they eat plants treated with the chemical or if they walk on surfaces that have just been sprayed and are still wet.

In humans, inhaling products that contain capsaicin can also cause coughing, difficulty breathing, production of tears, nausea, nasal and severe eye irritation, as well as temporary blindness, according to the NPIC and Roger Dickens, technical services manager at Terminix.

Dickens recommends wearing rubber gloves and eye or face protection when applying products that contain capsaicin to the plants or flowers in your garden.

While capsaicin can work as a temporary animal and insect repellent, Sanchez and Traunfeld say there are long-term management options gardeners may want to consider to keep out wildlife, such as exclusionary techniques like fencing, caging, row cover, insect netting and tulle.

“The problem is you would need to apply a sufficiently high concentration of capsaicin in the right locations and then maintain it through the season,” Traunfeld explained.

“But sunlight, rain and irrigation water, and soil particles would dilute it over time. Plus, mammals can become desensitized to capsaicin through regular exposure,” he added.

The Environmental Protection Agency (EPA) has registered several pesticide products that contain capsaicin for use on gardens, shrubs, lawns and other residential sites to deter and repel pests. For more information on those products, visit the EPA’s Pesticide Product and Label System (PPLS) website. 

This story is also available in Spanish / Lee este artículo también en español: Sí, la pimienta de cayena puede ayudar a mantener la vida silvestre fuera de tu jardín