Plants That Repel Cockroaches: What Works, What Is Safe and What Grows in Canada

Do Plants That Repel Cockroaches Actually Work?

Plants that repel cockroaches work only in a limited way: their oils repel or kill roaches in lab tests, but no study shows that a living plant keeps them out of a home. The repellent compounds are real. The problem is the gap between a concentrated oil in a test arena and a pot of herbs in your kitchen.

What Does the Research Show?

The research on plants and cockroaches is mostly lab work on extracted oils. The best-known studies come from Iowa State University. In 2002, researchers reported that catnip oil repelled German cockroaches, and that its main compound, E,Z-nepetalactone, was more active than an equivalent dose of DEET, the active ingredient in many bug sprays. Roaches with their antennae removed did not react, which suggests the effect works through smell.

A 2004 follow-up study found that catnip oil repelled American cockroaches as well as or better than DEET in the short term. More recently, a 2025 study in the journal Insects applied pure lavender, peppermint and rosemary oils directly onto German cockroaches. Lavender was reported to knock them down within seconds and kill them within 24 hours, and peppermint and rosemary also killed them within 24 hours.

Why Is a Potted Plant Not Enough?

A potted plant is not enough because the useful compounds stay mostly inside the leaves, and the oils that do escape are volatile. The authors of the 2025 study point out that this volatility reduces any lasting effect, that their doses were higher than in commercial products, and that lab conditions contrast sharply with real homes.

Iowa State's work on hedge apples (Osage orange fruit) shows the same pattern. Its researchers found compounds in the fruit that repel cockroaches, yet the university's extension service says whole fruit "have not been proven to repel or control insects in the home." A whole plant on a shelf may be in the same position: the chemistry may be there, but not at a dose that stops roaches looking for food and water.

Where Do Cockroaches Live in Canadian Homes?

Cockroaches in Canadian homes live indoors, mostly in warm, damp spots such as kitchens, bathrooms, basements and around plumbing, according to Health Canada. The German cockroach, a tan to light brown roach about 1.3 to 1.6 cm long, is generally the most common indoor species, and it does not tolerate cold well. It usually arrives inside used furniture, food, bottles or shipping boxes, along with its egg cases.

That means a row of lavender along your foundation does little against roaches already living behind your fridge. Visit the cockroach hub for identification and control guides.

Which Plants Repel Roaches?

Plants that repel roaches, based on the research available, are mostly aromatic herbs, and catnip has the strongest evidence.

Catnip

Catnip (Nepeta cataria) is the best-supported plant that repels roaches. Its oil, and especially the compound E,Z-nepetalactone, repelled German cockroaches better than DEET in the Iowa State tests. Catnip is easy to grow in much of Canada: seed companies typically list it as hardy in zones 3 to 9, and it often self-sows readily. Keep in mind that it attracts cats, and the ASPCA lists it as toxic to cats in larger amounts.

Lavender

Lavender is a pleasant-smelling option whose oil killed German cockroaches on contact in the 2025 lab study. English lavender (Lavandula angustifolia) is generally the hardiest type, though the Ontario agriculture ministry notes its zone rating depends on the variety. The ASPCA lists lavender as toxic to dogs, cats and horses.

Mint

Mint, including peppermint, is one of the most common plants named for roaches, and peppermint oil reached full mortality in the 2025 lab test when applied directly to the insects. A growing mint plant releases far less oil than that. The ASPCA lists mint as toxic to dogs, cats and horses when large amounts are eaten. Our guide to peppermint oil for roaches covers how the oil is used.

Rosemary

Rosemary is the most pet-friendly herb on the list: the ASPCA lists it as non-toxic to dogs, cats and horses. Its oil was reported to kill German cockroaches in the 2025 lab study. Rosemary is tender, though. Penn State Extension rates it for about zones 8 to 10, so in most of Canada it usually has to spend winter indoors.

Tea Tree

Tea tree is not really a plant you can grow against roaches in Canada. Tea tree (Melaleuca alternifolia) is a shrub or small tree native to eastern Australia, and tea tree oil is usually distilled from its leaves and twigs. What people usually mean is the oil, which some pest control companies mix into homemade sprays. Concentrated tea tree oil is also dangerous for pets.

Chrysanthemums

Chrysanthemums are not a cockroach repellent as a garden plant. Their reputation comes from pyrethrins, natural insecticides found in the flowers of some chrysanthemums and sold as pyrethrum powder or in registered sprays. A pot of garden mums does not release pyrethrins into the air.

Pyrethrins are chemicals, not a chemical-free option, and the ASPCA lists chrysanthemums as toxic to dogs, cats and horses. Health Canada also warns that boiling chrysanthemums to extract toxins is a dangerous homemade pesticide practice.

Other Plants Often Listed

Other plants often listed as roach repellents include citronella, marigolds and pitcher plants. No research on these plants and cockroaches was found, so treat those claims with caution. Bay leaves and citrus also come up often: see whether bay leaves work against roaches.

Are Cockroach Repellent Plants Safe for Pets?

Cockroach repellent plants are not all safe for pets: the ASPCA lists lavender, mint and chrysanthemums as toxic to cats and dogs, and catnip as toxic to cats. If you share your home with pets, choose and place these plants carefully.

Toxic Plants

Toxic plants on the usual lists cause mostly digestive signs. According to the ASPCA, lavender can cause nausea, vomiting and loss of appetite; mint can cause vomiting and diarrhea when large amounts are eaten; catnip can cause vomiting and diarrhea in cats; and chrysanthemums can cause vomiting, diarrhea, drooling, poor coordination and skin irritation. Keep these plants out of reach, and call your veterinarian if your pet chews on one and seems unwell.

The Pet-Safe Choice

Rosemary is the pet-safe choice among the herbs usually recommended for roaches. The ASPCA lists it as non-toxic to dogs, cats and horses, which makes it the easiest plant to keep on a kitchen windowsill in a home with pets.

Essential Oils and Pets

Essential oils are far more concentrated than the plants they come from, and that changes the risk. According to Pet Poison Helpline, even a few drops of concentrated tea tree oil applied to the skin or swallowed can severely poison a dog or cat, while products with about 1 to 2% tea tree oil or less are generally considered non-toxic when used as labelled. Cats are especially at risk of liver injury. Never apply oils to your pet or spray them where pets sleep or eat, and ask your veterinarian before using any oil-based product around them.

How Do You Use Plants to Repel Roaches at Home?

Plants to repel roaches work best as a small extra layer near entry points and damp spots, on top of cleaning and sealing.

Indoor Pots

Indoor pots let you keep herbs close to where roaches show up. Place catnip, mint or rosemary on a sunny windowsill in the kitchen or near a back door, but not on food preparation surfaces. Do not overwater: a saucer of standing water or soggy soil adds the moisture roaches look for. For kitchen-specific habits, read how to prevent roaches in your kitchen.

Outdoor Beds

Outdoor beds suit the hardiest plants. Lavender and catnip can be planted near doors, patios and the foundation. Lavender generally needs well-drained soil and may not survive in waterlogged ground. Outdoor plants will not reach roaches already living indoors, so think of them as decoration with a small bonus.

Overwintering Rosemary

Overwintering rosemary indoors is necessary in most of Canada. Penn State Extension advises growing it in a pot and bringing it inside about 2 to 3 weeks before the first fall frost, then setting it in a south-facing window in full sun or under a grow light.

Plant-Based Products

Plant-based products such as essential-oil sprays are where plant compounds are concentrated enough to matter. In Canada, any product sold to control pests should carry a Pest Control Products (PCP) number on its label, which shows Health Canada has approved it. Check that cockroaches are listed on the label and follow the directions. Our guides to cockroach repellents and essential oils for cockroaches compare the options.

Homemade Sprays

Homemade sprays made from herbs or oils are popular, but Health Canada warns that homemade pesticide recipes are not tested for their effects on health or the environment and may not work since they are not tested for effectiveness. Pest control companies also note that repellent sprays wash off and only suit minor problems. If you try one, label the bottle, keep it away from children and pets, and do not spray food surfaces.

What Works Better Than Plants to Keep Cockroaches Away?

Cleaning, sealing and baits work better than plants because they remove what roaches need and kill the roaches you cannot see. Health Canada stresses that pesticides alone will not succeed without intensive cleaning, and the same is true of plants.

Sanitation

Sanitation takes away the food and water that keep roaches in your home. Health Canada recommends cleaning up spills right away, storing food in sealed plastic or glass containers rather than cardboard, taking out the garbage daily, not leaving dirty dishes overnight, not leaving pet food out all day, and vacuuming often. Fixing leaks and running a dehumidifier in damp areas also helps. Our full guide to preventing cockroaches goes further.

Sealing Entry Points

Sealing entry points cuts off the paths roaches use to move in and between rooms. Caulk cracks, crevices and gaps around pipes, and cover vents, open pipes and drains with fine mesh screens. Roaches often arrive in boxes and second-hand furniture, so inspect items before bringing them inside, especially if you are moving and want to avoid bringing roaches with you.

Baits

Baits reach roaches where plants cannot. Roaches eat the bait and die later, and Health Canada notes that bait stations kill them about 48 to 96 hours after they eat it. Choose a product that lists cockroaches and has a PCP number on the label, as Health Canada advises, place it in dark spots where roaches hide, and keep it away from children and pets. See our tested picks for the best cockroach killer.

Diatomaceous Earth

Diatomaceous earth is a fine powder that dries out insects that walk through it. Health Canada describes it as non-toxic to humans and pets and says it remains active as long as it is kept dry, and you should avoid breathing in the dust. Follow the label, and use a product with a PCP number if you buy it to control insects.

When to Call a Pest Control Professional

Calling a pest control professional makes sense when you find roaches in several rooms or still see them after a few weeks of cleaning and baiting. A licensed professional can identify the species and use baits, dusts or targeted treatments in cracks and crevices. You can get a quote from a recommended local exterminator through Pest Agent's referral form.