Companion Planting - Natural Pest Control Hero

Companion planting is a natural, sustainable and eco-conscious methods to protect crops and reduce the need for chemical pesticides. Companion planting involves growing specific plants in proximity to support growth, deter pests, and foster a balanced ecosystem. While it can enhance yield and flavor, one of its most celebrated benefits is natural pest control.

Certain plants exude volatile organic compounds (VOCs) or other substances that repel pests or mask the scent of nearby crops. Others act as trap crops, luring harmful insects away from valuable vegetables. Some host beneficial predatory insects, keeping pest populations in check. A 2023 study from the University of California, Davis, found that interplanting marigolds with tomatoes reduced whitefly infestations by over 50%, while companion dill plantings led to a 60% increase in predatory insect presence.

Companion planting is part of a broader shift toward regenerative agriculture, which emphasises biodiversity, soil health, and minimal synthetic inputs. It also aligns with permaculture principles and supports wildlife-friendly gardening. Companion planting is about restoring relationships between plants, insects, and the soil.

Matchmaking for Plant Protection

Some popular companion pairings include:

  • Basil and Tomatoes: Not only does basil enhance the flavor of tomatoes, but it also repels whiteflies, mosquitoes, and tomato hornworms.

  • Carrots and Onions: The strong scent of onions confuses carrot flies, while carrots can help loosen the soil around onions.

  • Cabbage and Nasturtiums: Nasturtiums attract aphids away from cabbage and other brassicas, essentially acting as a decoy plant.

  • Corn, Beans, and Squash: Known as the “Three Sisters” of Indigenous agriculture, these plants support each other physically and nutritionally, while also helping deter pests.

  • Chives near roses deter aphids.

  • Add mint near cabbage or broccoli (but keep it in pots—it spreads quickly!).

  • Dill and fennel attract predatory insects like ladybugs and lacewings.


Here are some of the most effective—and surprising—plant partnerships that gardeners are using to combat common pests:

🌼 Marigolds: Universal Pest Repellent

  • Repels: Nematodes, aphids, whiteflies, cabbage worms

  • Pairs well with: Tomatoes, beans, cucumbers, peppers

French marigolds (Tagetes patula) secrete thiophenes, natural insecticides that deter root nematodes and a range of soft-bodied insects. Plant them as borders or between vegetable rows for maximum effect.

🌿 Basil + Tomatoes: Aromatic Armor

  • Repels: Tomato hornworms, whiteflies, mosquitoes

  • Bonus: Improves tomato growth and flavor

Basil’s strong scent interferes with pest detection, and its flowers attract pollinators and beneficial wasps. Plant basil at the base of tomato plants and harvest both through the summer.

🧅 Onions + Carrots: Scent Confusion

  • Onions repel: Carrot flies

  • Carrots repel: Onion flies

This classic combo uses mutual masking—the onion’s pungent scent hides the carrots from their predators, and vice versa. Bonus: both thrive in similar soil conditions.

🌱 Radishes + Spinach: Flea Beetle Bait

  • Radishes attract: Flea beetles away from spinach

Here, radishes act as a sacrificial crop, drawing flea beetles away from more delicate greens. Interplant radishes early in the season to protect spinach seedlings.

🥦 Cabbage + Nasturtiums: Trap and Repel

  • Nasturtiums repel: Whiteflies, squash bugs

  • Attract: Aphids away from brassicas

Nasturtiums produce a peppery scent and serve as a visual and olfactory decoy, pulling aphids away from cabbage, kale, and Brussels sprouts. Bonus: their flowers are edible and vibrant.

🌽 The “Three Sisters”: Corn + Beans + Squash

An ancient Indigenous practice:

  • Corn: Provides a natural trellis for climbing beans

  • Beans: Fix nitrogen in the soil

  • Squash: Large leaves shade out weeds and deter pests like raccoons with prickly vines

Together, these crops form a symbiotic trio that improves soil health, conserves moisture, and reduces pest damage.

🐞 Dill + Cabbage Family Crops: Ladybug Magnet

  • Dill attracts: Ladybugs, lacewings, parasitic wasps

  • Protects: Broccoli, kale, cauliflower

Let dill flower to attract beneficial insects that feast on aphids, cabbage worms, and more. Use dill as a companion for brassicas, which often suffer from pests that biological control agents can suppress.

🪴 Mint + Cabbage or Peas: Scent-Based Deterrent

  • Repels: Cabbage moths, aphids, ants

Mint's potent aroma masks the scent of crops vulnerable to infestation. However, mint spreads aggressively—plant in containers and bury the pots in the ground near crops for control.

🌻 Sunflowers: Pest Decoys & Pollinator Magnets

  • Attracts: Aphids, stink bugs (away from other crops)

  • Hosts: Pollinators and beneficial insects like parasitic wasps

Use sunflowers as a tall, colorful barrier that draws pests away while increasing garden biodiversity. They can also act as a windbreak and natural trellis.

✳️ Additional Proven Pairings:

Companion PairingPest Control BenefitTomatoes + BorageRepels tomato hornworm; attracts pollinatorsLettuce + ChivesDeters aphids and improves flavorBeans + RosemaryRepels Mexican bean beetlesCucumbers + TansyDeters ants, cucumber beetlesPotatoes + HorseradishDeters Colorado potato beetle



Getting Started: Tips for Success

  • Start small: Choose 2–3 proven pairings based on your crops.

  • Observe: Watch how pests, pollinators, and plants respond over time.

  • Rotate and experiment: Some combinations work better in certain climates and soils.

  • Avoid antagonists: Not all plants get along—avoid planting onions near beans, or fennel near most vegetables.



Final Thoughts

Whether you're a seasoned grower or a first-time gardener, companion planting offers a powerful, pesticide-free way to manage pests and promote harmony in your garden. It's clear that nature knows best—and sometimes, it’s all about choosing the right neighbors.



For our compiled list of companion planting, please click here.

Sophie Gautier