by Brenda Peterson

Companion planting is one of the simplest ways to grow a healthier, more productive garden—without relying heavily on chemicals or constant intervention. By intentionally placing certain plants near one another, you can improve growth, deter pests, enrich the soil, and even enhance flavor.

At its core, companion planting is about relationships. Just like people, some plants thrive together, while others prefer a little distance.

What Is Companion Planting?

Companion planting is the practice of growing different plants close together so they benefit one another.

These benefits can include:

• Natural pest control
• Improved pollination
• Better use of space
• Soil enrichment
• Shade or structural support
• Enhanced flavor

This method has been used for centuries in traditional agriculture, most famously in the Native American “Three Sisters” planting system.

The Three Sisters: A Time-Tested Example

The “Three Sisters” method pairs:

• Corn – provides a natural trellis
• Beans – fix nitrogen in the soil
• Squash – spreads along the ground, shading soil and suppressing weeds

Together, these three crops support one another in a balanced, productive system. It’s a beautiful reminder that diversity strengthens a garden.

MGOFDC members at the Heirloom Vegetable Garden, Tennessee Agricultural Museum, Ellington Agricultural Center, provide a yearly hands-on workshop regarding the Native American companion planting method “Three Sisters” for Master Gardener members and interns to learn about sustainable gardening practices and experience a piece of agricultural history.

Popular Companion Plant Pairings

Here are some tried-and-true combinations:

• Tomatoes + Basil

Basil may help repel insects like hornworms and whiteflies while potentially improving tomato flavor. Plus, they pair perfectly in the kitchen.

• Carrots + Onions

Onions help deter carrot flies, while carrots don’t compete heavily with onions underground.

• Cucumbers + Nasturtiums

Nasturtiums act as a trap crop for aphids and beetles, drawing pests away from cucumbers.

• Lettuce + Radishes

Radishes mature quickly and help break up the soil for shallow-rooted lettuce.

• Marigolds + Almost Everything

Marigolds are famous for deterring nematodes and certain pests. They also attract beneficial insects.

Plants That Don’t Get Along

Just as some plants thrive together, others compete or inhibit growth. A few combinations to avoid:

• Beans and onions
• Tomatoes and potatoes (can share diseases)
• Fennel with most vegetables (it tends to inhibit growth)

How Companion Planting Helps Your Garden

• Natural Pest Management

Certain plants repel harmful insects or attract beneficial predators like ladybugs and lacewings.

• Improved Soil Health

Legumes like beans and peas add nitrogen back into the soil, benefiting neighboring plants.

• Efficient Use of Space

Tall plants can provide shade for sun-sensitive crops, while ground covers reduce weeds and retain moisture.

• Increased Biodiversity

Diverse plantings create a more resilient garden ecosystem.

Getting Started

You don’t need to redesign your entire garden overnight. Start small:

• Add herbs among vegetables
• Interplant flowers with crops
• Mix root crops with leafy greens
• Avoid planting large monoculture blocks

Observe what works in your space. Gardening is as much about learning as it is about growing.

A Gentle Reminder

And, last but not least, companion planting isn’t magic—it’s strategy. Results can vary based on climate, soil conditions, and local pest populations. But even small changes can create noticeable improvements.

By working with nature instead of against it, you create a garden that feels balanced, abundant, and alive.