Companion planting is simple: certain plants thrive when grown near each other.

Tomatoes and basil are a classic example.

Basil may:

Repel aphids and whiteflies
Improve airflow between plants
Potentially enhance tomato flavor

Other strong combinations:

Carrots + onions
Corn + beans + squash (Three Sisters)
Marigolds + almost everything

Think of your garden as a community, not individual plants.

Diversity builds strength.