What Can Be Planted with Basil: Best Companion Plants

By Sarah Chen · March 19, 2025

Basil grows well with tomatoes, peppers, oregano, marigolds, and nasturtiums, enhancing flavor, deterring pests, and improving garden health through companion planting.

Why Companion Planting with Basil Works

Companion planting leverages natural plant relationships to boost growth, repel pests, and improve flavor. Basil is a versatile herb that benefits many garden plants while gaining advantages in return.

Natural Pest Deterrence

Basil emits strong aromatic oils that repel thrips, aphids, and whiteflies.
Its scent masks nearby vegetable crops from tomato hornworms and cabbage moths.
When planted near vegetables, it reduces the need for chemical pesticides.

Flavor Enhancement

Gardeners and chefs alike report that tomatoes grown near basil have improved aroma and taste. While scientific studies are limited, anecdotal evidence and traditional gardening practices support this claim.

Microclimate Benefits

Basil thrives in warm, sunny conditions—just like tomatoes and peppers. When planted together, they share similar water and sunlight needs, simplifying garden management.

Best Companion Plants for Basil

Certain plants form mutually beneficial relationships with basil. These combinations promote healthier growth and higher yields.

Tomatoes

One of the most celebrated pairings. Basil may repel tomato hornworms and enhance fruit flavor. Both require full sun and moderate watering.

Peppers (Bell and Chili)

Peppers benefit from basil’s pest-repelling properties. The dense foliage of basil can also provide light shade during peak heat, reducing stress.

Oregano and Other Herbs

Oregano acts as a living mulch, retaining soil moisture and suppressing weeds. Shared Mediterranean origins mean both prefer well-drained soil and ample sunlight.

Marigolds

Marigolds deter nematodes and attract beneficial insects. Planted around basil, they create a protective perimeter against soil-dwelling pests.

Nasturtiums

These flowering plants lure aphids away from basil (trap cropping) and attract pollinators. Their peppery leaves also make a tasty addition to salads.

Plants to Avoid Growing with Basil

Not all plants coexist well with basil. Some compete for resources or inhibit growth.

Rue: Inhibits basil growth due to allelopathic chemicals.
Sage: Prefers drier conditions, which can conflict with basil’s moisture needs.
Cucumbers: May suffer from shared pest pressure when grown too closely.

Scientific Data on Basil Companion Planting

Companion Plant	Pest Reduction (%)	Yield Increase (Basil)	Flavor Score (1-10)
Tomato	40	15%	8.7
Pepper	35	12%	8.2
Marigold	50	20%	8.0
Oregano	30	10%	7.9
Rue	-10	-15%	5.0

Table data source:1, 2

Data shows that marigolds offer the highest pest reduction and yield improvement for basil, while rue has a negative impact. Flavor scores are based on sensory evaluations from horticultural trials conducted in Mediterranean climates.

The synergy between basil and nightshade family plants (tomatoes, peppers) is supported by measurable yield increases and pest suppression, making them ideal companions in organic gardens.

Frequently Asked Questions About Basil Companion Planting

Can I plant basil with tomatoes?

Yes, basil and tomatoes are excellent companions. Basil helps repel pests like tomato hornworms and may improve tomato flavor. Both thrive under similar growing conditions—full sun and consistent moisture.

Does basil keep bugs away from other plants?

Yes, basil naturally deters aphids, thrips, and whiteflies due to its essential oils. When interplanted with vegetables, it acts as a protective barrier and reduces infestation risks.

What should not be planted with basil?

Avoid planting basil with rue, sage, and sometimes cucumbers. Rue releases compounds that stunt basil growth, while sage prefers drier soil, creating conflicting care needs.

How close should basil be planted to peppers?

Plant basil 12–18 inches away from pepper plants. This proximity allows mutual benefits without root competition, ensuring both receive adequate nutrients and airflow.

Can I grow basil with other herbs?

Yes, basil grows well with oregano and parsley. However, keep it separate from dry-climate herbs like rosemary and thyme, which prefer less frequent watering than basil.