10 Plants That May Help Repel Bugs Like Mosquitoes, Flies, Spiders, and More

When it comes to the inevitable face-off between you and bugs, keeping them away from your immediate vicinity is probably top priority as they thrive during the warmer months. While there are always options like pesticides and bug traps, it certainly doesn’t hurt to explore potential natural solutions before trying harsher chemicals (even though they can be necessary with serious infestations).

That’s where plants come in. There are a slew of different herbs, bushes, and flowers you can put in your garden or outdoor space that have a solid reputation for keeping bugs away. “Plants are in the business of repelling insects, because this is one of the most important ways to avoid insect damage—by feeding,” explains entomologist Roberto M. Pereira, Ph.D., an insect research scientist with the University of Florida. But, of course, plants also need insects to perform cross-pollination so they can survive. “It is an arms race between plants and insects, each trying to survive and prosper,” Pereira says.

Not sure where to start? Below, we rounded up the plants gardeners love to use to repel annoying bugs. They won’t wipe out mosquitoes, ticks, or flies for good—no plant really will—but their unique properties may send pests in another direction while simultaneously sprucing up your yard, garden space, or patio.

You’re probably most familiar with citronella candles to repel mosquitoes, but the smell comes from a plant called Cymbopogon nardus, which gives off a distinct beach grass vibe. It’s the oil from the plant that’s actually the repellent, according to the National Pesticide Information Center (NPIC).

But Pereira says you’d need to have a lot of them to mimic the concentrated effects of burning a citronella candle or torch, so you shouldn’t rely on plants alone to keep mosquitoes away.

If you just want one citronella plant, though, consider placing it in a pot near an outdoor seating area. “This plant gives off very little aroma—you can smell it if you crush the leaves—and so would only work if you were sitting right up close to it,” says board-certified entomologist Nancy Troyano, Ph.D., director of operations education and training for Ehrlich Pest Control.

Lemongrass is a tall, perennial grass that’s native to tropical and sub-tropical climates of Asia. It looks a lot like citronella grass, and also has similar mosquito-fighting properties, Pereira says.

One scientific literature review found that lemongrass oil offered up to 95% protection against certain types of mosquitoes for 2.5 hours, while another study found the oil can deter stable flies in a lab setting. Keep in mind, though, that it was the oil that was studied—not the plant itself. But if you’d like to add a few to your yard to see if they help, it’s a great place to start.

Many commercial bug repellents contain plant essential oils, and peppermint oil (which comes from peppermint plants) is one of the most promising when it comes to warding off mosquitoes, research suggests, as well as certain spiders.

But it’s not clear why, exactly, some bugs don’t love it, Pereira says, although the strong smell may have something to do with it. Again, studies have mainly been done on various mint oils, not the plants.

Another hack to consider: You can combine 10 drops each of peppermint, thyme, and rosemary essential oils mixed with water in a spray bottle. Then, spritz the solution around your garden to help repel flies, fleas, mosquitoes, aphids, ants, spiders, chiggers, and more.

Catnip is known for its ability to give your feline friends a mellow buzz, but the herb also has some bug repellent properties. One study found the essential oil from catnip can help deter houseflies and mosquitoes. Another study from Iowa State University also found catnip oil to be a more effective “spatial repellent” than DEET, the most popular ingredient in insect repellents. Same caveat, though: Catnip oil isn’t the same as actual catnip plants, but the results are promising enough to warrant adding a few to your yard if you don’t have cats to worry about.

This herb has a reputation for getting rid of ants, flies, and mosquitoes, but there isn’t a ton of science to support the claims outside of mosquitoes. Research has found that having a pot of sage around can offer up to 32% protection against certain types of mosquitoes. Since that’s 32% more protection than you’d get with no repellent, it’s not a bad idea to consider sage in the future, especially if you enjoy adding fresh sprigs to your meals.

These colorful annuals have the potential to keep away bugs like aphids, certain beetles, leafhoppers, and squash bugs. But, keep in mind that you need them to bloom to do their thing. Petunias’ potential bug-repellent properties “may only be there if flowers are present,” Pereira says.

Marigolds contain pyrethrum, an insecticidal compound that’s used in bug repellents. There isn’t a ton of research on the effects of marigolds on insects, but gardeners have long sworn by them to keep annoying pests, like mosquitoes and destructive nematodes, at bay. These annuals, while gorgeously vibrant, have an off-putting smell that many bugs (and people!) don’t seem to like. Try using them to create a pretty border around your patio, or place potted marigolds near common entryways, like doors and windows. (Just keep arrangements away from tables, where they may attract bees and wasps!)

This spiky herb, thanks to its particularly pungent scent, may help keep mosquitoes away, Troyano says. In fact, research
has found that, when compared to 11 other essential oils, rosemary had the longest repellent effects on mosquitoes, and may even deter other insects like aphids and spider mites—just note that these results were all based on rosemary oil.

Research has found that lavender can be effective at repelling mosquitos and other arthropods. It’s not clear why the flowering plant can act as a repellent, though—it could just be that the smell doesn’t appeal to bugs, Pereira says. “What is pleasant to you does not have to be pleasant to other humans, other mammals, other vertebrates, or other animals including invertebrates such as mosquitoes,” he says.

A study published in the Journal of Vector Ecology found that basil—specifically hairy basil—knocked down and killed certain types of mosquitoes 100% of the time. Here’s the thing: This was tested in essential oil form, which is likely to be more potent at fending off mosquitoes than the actual plant. Overall, though, Pereira says the plant “produces a repellent odor” that mosquitoes don’t like.