23 Plants That Keep Garden Pests Away Without a Single Chemical
I didn’t think much about the marigolds my grandmother planted around every single vegetable bed until someone told me why she did it. Turns out it wasn’t just decoration.
A lot of common plants, herbs you probably already have, flowers you’d buy just because they’re pretty, are quietly doing pest control work the whole time they’re sitting there. Some repel bugs outright. Some trick them into going somewhere else entirely.
We ranked twenty-three of them from solid but ordinary all the way up to the one gardeners swear by more than anything else. The last one does something underground that most people have never even heard of.
23. Oregano
Oregano’s got a lot going for it in the kitchen, but its strong smell does double duty in the garden too. The same aromatic oils that make it useful in cooking, carvacrol specifically, seem to keep aphids and cabbage loopers from settling in nearby.
It also pulls in a few beneficial insects along the way, which never hurts.
Plant it near broccoli or other brassicas and it grows easily in a pot or a border, so you’re basically getting a low effort herb supply with a mild pest deterrent built in.
22. Parsley
Here’s one that works less by repelling and more by recruiting. Parsley attracts hoverflies and parasitic wasps, both of which happily prey on aphids once they show up.
Its scent can also throw off certain pests a little, though that part’s more subtle than the insect recruitment angle.
It grows well tucked in next to tomatoes or asparagus, and since you’re already using the leaves and stems in the kitchen, interplanting it costs you basically nothing in space.
21. Savory
Savory doesn’t get talked about much outside of bean dishes, but its peppery, strong scent does some work in the garden too, mostly keeping bean pests and general insects at a distance.
It stays low growing and easy to maintain, which makes it a nice companion to other Mediterranean herbs if you’re already growing thyme or sage nearby.
Use it as a border plant around beans specifically, that’s where the effect seems most useful.
20. Cilantro
Cilantro’s fragrance is strong enough that it pulls in predatory insects the same way parsley does, which then take care of aphids and other pests hanging around your tomatoes.
It grows fast and bolts once the heat kicks in, but it reseeds readily, so succession planting keeps a steady supply going both for cooking and for the pest support.
Plant it near tomatoes and just keep replanting through the season for the best effect.
19. Borage
Borage does something a little more clever than most herbs on this list. Its star shaped blue flowers pull in slugs and snails almost like a decoy, while at the same time deterring tomato hornworms and cabbage worms.
Pollinators love it too, which makes it a genuinely useful multitasker in a vegetable garden.
It self seeds on its own and even adds minerals back into the soil. Scatter it around tomatoes or strawberries and let it do both jobs at once.
18. Thyme (including Lemon Thyme)
Bruise a thyme leaf and you’ll notice the smell gets a lot stronger fast, and that’s exactly the point. The compounds released deter mosquitoes, whiteflies, and hornworms, and there’s actual research behind its effect on cabbage pests specifically.
It’s drought tolerant once it’s established and some varieties stay evergreen year round.
Plant it near a patio where you’ll brush past it, or tuck it in with your brassicas, and let the leaf contact do the work.
17. Sage
Sage’s fuzzy leaves carry a scent that cabbage moths, carrot rust flies, and various beetles seem to avoid. It’s a solid, if quiet, addition to a vegetable garden.
It handles drought well and the silver toned foliage adds some visual contrast against greener plants, which is a nice bonus if you care about how the bed looks.
Border your carrots or brassicas with it, then harvest what you need for cooking on the side.
16. Petunia
Petunias aren’t just filler color for a container garden. Their stamens are sticky enough to actually trap small pests like aphids and leafhoppers that land on them.
On top of that, they seem to repel tomato hornworms and squash bugs, which makes them more functional than most people give them credit for.
Since they come in such a wide color range, planting them near beans or tomatoes doubles as easy visual monitoring, you’ll notice pest activity on the flowers before it spreads.
15. Scented Geranium
Scented geraniums lean into fragrance in a way regular geraniums don’t, and that fragrance happens to deter mosquitoes, leafhoppers, and corn earworms.
They work well in pots, and there are enough varieties out there that you can pick one based on scent preference as much as pest control.
Put them in high traffic areas of the yard or near roses and corn, anywhere you’d benefit from the mosquito deterrent most.
14. Cosmos
Easy to grow and long blooming, cosmos pull in predatory insects like lacewings and wasps, both of which go after garden pests on their own once they’re established nearby.
They also seem to repel corn earworm specifically, which is a nice bonus if that’s ever been an issue for you.
Since they’re drought tolerant and low maintenance, scattering seeds directly into a vegetable bed is about as low effort as pest support gets.
13. Dill
Dill’s feathery growth is mostly known for pickles and fish, but let it flower and it becomes a serious draw for beneficial wasps and hoverflies, the same predators that keep aphids in check elsewhere on this list.
At the same time, it repels cabbage loopers and hornworms directly.
The flowering part matters here, that’s when the predator attraction really kicks in, so plant it near your cabbage family crops and let it go to flower instead of harvesting it all early.
12. Chrysanthemums
Chrysanthemums contain pyrethrum, which is the natural compound a lot of commercial insecticides are actually based on. Having the plant itself in the garden repels ants, roaches, beetles, ticks, and more.
They come in a huge range of varieties and hold up well as cut flowers if you want to bring some inside too.
Planting them as a border around a bed gives you a broader spectrum effect than most single purpose herbs on this list.
11. Tansy
Tansy’s yellow button flowers come with a strong, traditional reputation for repelling ants, flies, and a wide range of beetles.
It does attract some beneficial insects on top of that, but it comes with a real caveat, tansy can be invasive if you let it spread unchecked.
Keep it contained in a pot near whatever problem area you’re dealing with rather than planting it directly in open soil.
10. Wormwood
Wormwood’s silvery foliage and bitter scent make it a potent repellent against moths and beetles, and it’s strong enough that deer and rabbits tend to avoid it too.
That potency is also the catch. Wormwood has allelopathic tendencies, meaning it can suppress the growth of plants around it if you’re not careful.
Use it sparingly as a border rather than mixing it directly into a bed, the effect works best kept at a bit of a distance.
9. Fennel
Fennel’s a little unusual on this list because its effect isn’t purely repellent. It keeps a lot of pests away, but it also attracts beneficial insects and can even act as a trap for a few specific ones.
It grows tall with a licorice flavored bulb and leaves that are genuinely useful in the kitchen.
Because of its mixed effect, it works better planted apart from some vegetables and closer to others, so it takes a little more planning than most herbs here.
8. Alliums (Chives, Onions, Garlic)
The sulfur compounds that make onions and garlic smell so strong are also what makes them effective against aphids, carrot flies, slugs, and Japanese beetles.
Garlic in particular has a broad effect across a wide range of pests, and since the whole family is edible, you’re never wasting the space.
Plant them densely alongside carrots or roses, that combination shows up again and again in companion planting guides for good reason.
7. Mint (including Peppermint)
Mint’s oils are potent enough to repel aphids, ants, cabbage moths, mosquitoes, and fleas all at once, which makes it one of the more broadly useful plants on this entire list.
There’s a real catch though. Mint spreads aggressively once it’s in the ground, to the point where a container isn’t optional, it’s essential.
Keep it in pots near entryways or close to your vegetables and you get the pest benefit without it taking over the whole yard.
6. Catnip
Catnip repels an unusually wide range of pests, mosquitoes, flea beetles, Japanese beetles, squash bugs, and even cockroaches, all thanks to a compound called nepetalactone.
It’s a mint relative, so it shares some of that same aggressive growth habit, and obviously it comes with one extra consideration if there are cats around who’ll want to roll in it.
Plant it in borders or pots, just keep it out of easy cat access if that’s a concern for you.
5. Rosemary
This is where the list stops being about single pest deterrents and starts covering a genuinely wide range at once. Rosemary’s aromatic oils effectively repel Japanese beetles, carrot flies, slugs, snails, and mosquitoes, all from one woody, drought tolerant shrub.
It’s also a kitchen staple, so you’re not planting it purely for pest control in the first place.
Grow it as a hedge or in a large pot near your vegetables or patio, and it just keeps working in the background year after year.
4. Lavender
Lavender has a reputation for being calming to people, which makes it a little funny that it’s simultaneously repelling mosquitoes, flies, fleas, and moths so effectively that its oils show up in commercial repellent products.
It’s also a serious pollinator magnet and deer tend to leave it alone entirely.
Plant it near a seating area or along a garden bed edge and you get the fragrance, the pollinators, and the pest deterrent all from the same few plants.
3. Nasturtium
Nasturtium works differently than almost everything above it on this list. Instead of repelling pests outright, it acts as a trap crop, deliberately drawing aphids, squash bugs, and cabbage moths onto itself and away from the vegetables you actually care about.
It’s also edible and genuinely pretty, with peppery flowers and leaves that work fine in a salad.
Plant it as a sacrificial border or let it sprawl as groundcover, either way it’s doing its job by taking the hit so your other plants don’t have to.
2. Basil
Basil’s strong aroma repels flies, mosquitoes, aphids, tomato hornworms, and asparagus beetles, which on its own would make it a solid entry. But it also seems to actively improve the health of tomatoes growing nearby, which is a rare combination of pest control and companion benefit in the same plant.
It grows quickly, comes in a lot of varieties, and pinching it back regularly keeps it bushy and productive.
Interplant it with tomatoes or peppers and you’re getting fresh pesto ingredients and pest support at the same time. Which brings us to the one gardeners mention more than any other.
1. Marigolds (especially French Marigolds)
Marigolds earned the top spot for something most people never even think about, what’s happening underground. Their roots release compounds called thiophenes, including one specifically named alpha terthienyl, that suppress root knot nematodes, a soil pest that causes real damage and is almost impossible to see coming until your plants are already struggling.
On top of that underground effect, marigolds also repel aphids and whiteflies above the surface through scent alone, and they’re easy and prolific enough that most gardeners can grow a dense border of them without much effort at all.
They pull in some beneficial insects too, and can work as a trap for certain pests the same way nasturtium does. But it’s that root level nematode suppression that separates marigolds from everything else on this list, a hidden soil problem getting handled by a flower most people just think looks nice.
Plant them densely around a vegetable bed or as a full border and you’re covering both the soil and the air at once, which is more than almost anything else here can claim.
Keep the Chemicals Out of Your Garden
None of this replaces good garden hygiene or means you’ll never see a single pest again, these plants reduce pressure, they don’t wipe it out completely. But swapping a few empty border spaces for something on this list is about as easy as garden upgrades get.
Worth trying even just one or two of these this season and seeing what actually changes.
