Fact check: Do mosquito repelling plants work?

A Facebook post from Simple Garden Life (5 pm on June 6, 2026) claims that mosquito repelling plants can make patios, porches and garden seating areas “feel fresher and more inviting.” It says that while no plant creates a perfect mosquito free bubble, many aromatic herbs and flowers contain fragrant oils that mosquitoes tend to dislike, especially when leaves are brushed, crushed or warmed by the sun.

The post is more careful than many social media graphics on this topic, but it still leaves readers with an impression that is stronger than the evidence supports.

Verdict

Partly true, but overstated.

Many aromatic plants do contain compounds that can repel mosquitoes. That much is true. The problem is that most of the research is on extracted oils, concentrated emulsions, crushed leaves, smoke, lotions or treated materials. That is very different from placing pots of basil, lavender, mint or lemongrass around a patio and expecting a noticeable drop in mosquito bites.

What the post gets right

The post is right that plants such as lemongrass, basil, mint, lavender, rosemary and sage contain aromatic compounds. Some of those compounds have shown mosquito repellent activity in studies.

It is also reasonable to say that crushing or bruising leaves releases more scent. The fragrance of mint or basil is much stronger when the leaves are handled because volatile oils are being released from the plant tissue.

The gardening advice is mostly fine too. Basil likes warm weather. Lavender needs full sun and excellent drainage. Mint should usually be grown in pots because it spreads aggressively. Rosemary and sage prefer sunny, well drained conditions. Bee balm is attractive to pollinators and does need good air movement to reduce powdery mildew.

The strongest part of the post is the advice to empty standing water. That is not a decorative solution, but it is one of the most important mosquito control steps around a home. Mosquitoes can breed in small amounts of stagnant water, including water in saucers, buckets, birdbaths, toys, old tires and clogged eavestroughs.

Where the post goes too far

The weak part is the suggestion that a mix of these plants around seating areas, doorways and walkways can play a “helpful role” in a mosquito conscious garden.

That may sound modest, but the practical question is this: will a few pots of herbs around a patio reduce mosquito bites enough for people to notice?

For that, the evidence is thin.

Studies showing mosquito repellency usually test essential oils or other concentrated plant preparations. A 10 percent volume by volume emulsion, for example, means the researchers are testing a preparation containing 10 millilitres of active ingredient in every 100 millilitres of finished mixture. That is not comparable to the tiny amount of scent drifting from a living plant in a pot.

This distinction matters. A basil plant can contain mosquito repellent compounds. That does not mean a basil plant on a table will protect the people sitting around it.

The citronella geranium problem

The post includes citronella geranium among plants that can help. That claim deserves special caution.

Citronella geraniums, often sold as “mosquito plants,” have been tested as living plants. In field studies, researchers found no significant reduction in mosquito landings or bites when the plants were present compared with when they were absent.

Health Canada also lists citrosa houseplants among products that do not protect well against biting insects.

That does not mean citronella scented geraniums are useless plants. They can be attractive, fragrant and enjoyable to grow. But they should not be sold or recommended as meaningful mosquito protection.

Lemongrass is not quite the same as citronella

The post says lemongrass contains citronella oil, “the same scent used in many mosquito repelling candles.” That wording is a bit loose.

Lemongrass and citronella grasses are related plants in the genus Cymbopogon, and their essential oils can contain some overlapping aromatic compounds. But commercial citronella oil is usually derived from citronella grasses such as Cymbopogon nardus or Cymbopogon winterianus, not ordinary culinary lemongrass, Cymbopogon citratus.

Lemongrass can be a useful, attractive container plant in summer, especially in warm sunny sites. In most of Canada, it is not winter hardy outdoors and should be treated as an annual or brought inside before frost. But growing lemongrass beside a chair is not the same thing as applying a tested repellent product.

What gardeners should actually do

Grow these plants if you like them. Basil, mint, lavender, rosemary, sage, marigolds, bee balm and lemongrass can be useful, beautiful and fragrant. Many are good for cooking. Some support pollinators. Some are excellent container plants.

Just do not treat them as your main mosquito control strategy.

For real mosquito reduction, start with water. Empty saucers, buckets, toys, tarps, birdbaths and anything else that holds stagnant water. Clean eavestroughs. Replace birdbath water regularly. Keep rain barrels tightly screened.

For personal protection, use a repellent approved for mosquitoes, such as products containing DEET or Picaridin, and follow the label. Also wear long sleeves, long pants and light coloured clothing, especially at dusk and dawn when many mosquitoes are active.

A fan is useful on a deck or patio because mosquitoes are weak fliers. This is more practical than relying on scented plants.

A fairer version of the claim

A more accurate version of the Facebook post would be:

Many aromatic garden plants contain compounds that can repel mosquitoes when extracted, concentrated, crushed, burned or used in formulated products. Simply growing these plants around a patio may add fragrance and beauty, but it should not be relied on for meaningful mosquito protection. The best home strategy is still to remove standing water and use approved repellents when bites matter.

That is less romantic than the Facebook post, but it is much closer to the evidence.