Basil Companion Plants: What to Grow and Avoid

The best companion plants for basil are tomatoes, peppers, oregano, chamomile, asparagus, and root crops like beets and carrots. Basil is mostly a giver in the garden: its aromatic oils mask and repel aphids, whiteflies, thrips, and even tomato hornworm, so the plants around it grow with less pest pressure. Many gardeners are convinced basil improves the flavor and vigor of nearby tomatoes, too. The main things to keep basil away from are sage and rue, which want very different conditions, and cucumbers if you are fussy about flavor.

The best companion plants for basil

Basil earns its keep through scent. Its aromatic oils mask the smell of the crops around it and drive off many soft-bodied pests, while its flowers, if you let a few open, feed bees and hoverflies. Here are the companion plants for basil that gardeners come back to year after year, and why each pairing works.

Tomatoes

This is the classic pairing, in the garden and on the plate. Basil helps repel aphids, whiteflies, and tomato hornworm, the pests that plague a tomato patch, and generations of gardeners feel their tomatoes taste better and grow stronger with basil at their feet. Tuck a basil plant beside each tomato and let a few flower. If you want the full picture, see our guide to tomato companion plants.

Peppers

Peppers and basil love the exact same warm, sunny, well-watered conditions, which makes them natural bedfellows. Basil helps repel the aphids and thrips that trouble peppers, and its low, leafy growth shades and cools the pepper's roots through the hottest weeks of summer. For more matches, read our guide to pepper companion plants.

Oregano and chamomile

Basil is happy among other aromatic herbs. Oregano shares its love of sun and warmth and adds another layer of pest-confusing scent to the bed. Chamomile is a classic herb-garden companion that is believed to improve the growth and essential-oil content of the herbs around it, and its little daisy flowers bring in beneficial insects.

Asparagus

Basil and asparagus are an old, reliable pairing. Basil is thought to help deter the asparagus beetle, one of the few serious pests of an asparagus bed, while the asparagus ferns give a little light shade. Planting basil along an asparagus row is an easy way to protect a crop that stays in the ground for years.

Root crops (beets and carrots)

Root vegetables like beets and carrots make tidy, low-competition neighbors for basil. They work the soil below while basil fills the space above, so the two rarely fight for light or room. Basil's scent can also help mask the carrots that carrot rust fly hunts by smell, giving the roots a little extra cover.

Let some basil flower

If you can spare a few plants, let part of your basil bolt and bloom. The flower spikes are covered in bees and hoverflies, and drawing those pollinators and predators in benefits every fruiting crop nearby, from tomatoes to peppers to squash. Pinch the rest of your basil to keep the leaves coming for the kitchen.

In every case the mechanism is the same: basil's aromatic oils do the pest work by masking and repelling insects, and the flowers feed the pollinators. That is what makes basil one of the most generous companion plants you can grow.

What not to plant near basil

Basil gets along with most of the garden, but a few neighbors are worth avoiding.

• Sage: Sage wants dry, lean soil and far less water than basil, which likes to stay evenly moist. Their needs pull in opposite directions, and their strong aromatics can clash, so give them separate beds.
• Rue: Rue is a traditional bad companion for basil and is best kept well away from it and from most culinary herbs.
• Cucumbers: This one is about taste, not health. Cucumbers can pick up strong nearby aromas, and some gardeners find basil growing right next to them carries into the cucumber's flavor. If that bothers you, plant them apart. For the cucumber's own best matches, see our cucumber companion plants guide.

The short version: match basil with plants that share its love of warmth, sun, and steady water, and keep it away from the dry-soil, strong-scented outliers like sage and rue.

Why companion planting works for basil

A few things make basil one of the most useful companions you can tuck into a bed.

• It repels pests. Basil's aromatic oils mask and repel aphids, whiteflies, thrips, tomato hornworm, and even some flies and mosquitoes, lowering pest pressure on its neighbors without any spray.
• It may improve flavor and growth. Generations of tomato growers are convinced their fruit tastes better and their plants grow stronger with basil nearby. It is hard to measure, but it is a belief with deep roots.
• It feeds pollinators when it flowers. Let some basil bloom and the flowers pull in bees and hoverflies that boost fruit set and help keep aphids in check across the whole garden.

How to lay out basil with its companions

Basil is easy to place because it asks for so little room. A few simple ways to put it to work:

• Interplant with tomatoes and peppers. Set a basil plant every 10 to 12 inches at the base of your tomatoes and peppers so its scent sits right where the pests gather.
• Edge the bed with basil. A low border of basil around a vegetable bed forms a fragrant, pest-repelling ring and keeps the leaves within easy reach for the kitchen.
• Pair it with other heat-loving herbs. Group basil with oregano and chamomile in a sunny herb bed where they all share the same warmth and watering.
• Let a few plants flower. Allow some basil to bloom for the bees while you keep the rest pinched back for a steady supply of tender leaves.

Give basil full sun, warm soil, and even moisture, and it will look after itself and its neighbors all season. Ready to start? Learn the full method in our basil growing guide, and browse heirloom varieties in the basil seeds collection.