The best examples of 3 companion planting examples for sustainable gardening

When people ask for real examples of 3 companion planting examples for sustainable gardening, the Three Sisters is usually the first story I tell. It’s an old Indigenous North American planting method that still works beautifully in modern backyards.

At its heart, the Three Sisters is a living teamwork project between:

• Corn
• Pole beans
• Squash (usually winter squash or pumpkins)

Instead of thinking of them as three separate crops, think of them as roommates sharing chores.

How the Three Sisters work together

Corn grows tall and straight, creating a natural trellis. The pole beans climb the corn stalks, so you don’t need to buy or build supports. While they’re climbing, the beans are also fixing nitrogen in the soil—thanks to bacteria on their roots—which helps feed the corn and squash over time.

Down at ground level, the squash sprawls out, shading the soil. Those big leaves act like living mulch, helping the soil hold moisture and blocking many weeds from sprouting. In a warming climate, with hotter summers and more erratic rainfall, this kind of natural shading and moisture retention fits right in with 2024–2025 sustainable gardening trends, which emphasize water-wise practices and soil protection.

Researchers and educators still highlight this system as a model of sustainable agriculture because it increases biodiversity in a small space and reduces the need for synthetic fertilizers and herbicides. For a deeper look at Indigenous agricultural knowledge, you can explore resources from the U.S. National Park Service and land-grant universities like Cornell University.

How to plant your own Three Sisters bed

You don’t need a field to try this example of companion planting. A small garden bed—about 4 feet by 4 feet—is plenty.

Start by planting corn in a block rather than a single row. Corn pollinates better in blocks, which means fuller ears. Once the corn is about 6 inches tall, tuck pole bean seeds around each stalk. A week or two later, plant squash seeds around the outer edge of the bed so they can trail outward.

Spacing will vary by variety, but a simple starting pattern is:

• A small block of corn in the center
• 1–2 bean seeds per corn stalk
• Squash plants circling the outside, with at least 2–3 feet between them so they can spread

This is one of the best examples of 3 companion planting examples for sustainable gardening because it hits so many goals at once: vertical layering, natural weed suppression, improved soil health, and a diverse harvest.

Extra companions to try with the Three Sisters

If you want to take this example of companion planting one step further, you can mix in:

• Sunflowers at the back of the bed as additional supports and pollinator magnets
• Marigolds around the edges to attract beneficial insects and help distract some pests

These extra plants increase biodiversity even more, which aligns with what organizations like the USDA promote for resilient, sustainable food systems.

2. Tomato, basil, and marigold: a backyard-friendly example of 3 companion planting examples for sustainable gardening

Another of the best examples of 3 companion planting examples for sustainable gardening is the classic tomato bed paired with basil and marigolds. This one is perfect if you’re working with raised beds, patio planters, or a tiny urban yard.

Here’s the trio:

• Tomatoes
• Basil
• Marigolds (French or signet marigolds are common choices)

This combination shows up constantly in real examples of companion planting because it fits both traditional gardening wisdom and modern sustainability goals.

Why this trio works so well

Tomatoes are heavy feeders and magnets for pests like aphids, whiteflies, and hornworms. Basil brings a strong scent that may help confuse or repel some pests, and many gardeners swear that tomatoes grown near basil taste better. While taste is subjective, it’s a widely reported experience.

Marigolds are the workhorses of this example of companion planting. Their flowers attract pollinators and beneficial insects like lady beetles and parasitic wasps, which prey on common tomato pests. Some species of marigolds also produce compounds in their roots that can help suppress certain soil-dwelling pests like root-knot nematodes over time. Extension services, such as those linked from USDA’s National Institute of Food and Agriculture, often mention marigolds in integrated pest management guides.

In 2024–2025, more home gardeners are leaning into natural pest control instead of broad-spectrum pesticides. This tomato–basil–marigold trio fits that trend perfectly.

How to arrange tomato, basil, and marigold together

Picture a simple raised bed or a long in-ground row.

Plant your tomatoes first, giving each plant enough space according to the seed packet or plant tag—usually 18–24 inches apart for determinate varieties and up to 24–30 inches for indeterminate types.

Then, tuck basil plants between or just in front of the tomatoes. You can plant basil closer together—about 8–12 inches apart—because it stays smaller and tolerates a bit of crowding.

Finally, plant marigolds along the front edge or at the corners of the bed. They’ll form a colorful border that also works as a living pest-management system.

This layout is one of the best examples of 3 companion planting examples for sustainable gardening because it layers:

• Tall, sun-loving tomatoes in the back
• Medium-height basil in the middle
• Short marigolds at the front

You get a mini ecosystem in a single bed, with flowers for pollinators, herbs for the kitchen, and tomatoes as the main crop.

Extra companion ideas around tomatoes

To expand this example of companion planting even more, you can add:

• Nasturtiums trailing over the edge of the bed; they’re known as “trap crops,” often attracting aphids away from your tomatoes
• Garlic or chives near the base of the bed; their scent can help confuse some pests and they barely take up any room

Together, these create a mixed-planting zone that supports beneficial insects, improves flavor variety in your kitchen, and aligns with current sustainable gardening practices that encourage plant diversity over monoculture.

3. Carrot, onion, and lettuce: a cool-season example of 3 companion planting examples for sustainable gardening

Not every gardener wants towering corn or sprawling squash. If you prefer tidy beds and spring or fall harvests, this trio is one of the most practical examples of 3 companion planting examples for sustainable gardening:

• Carrots
• Onions (or scallions)
• Lettuce

This combination is especially handy for smaller gardens and people who like to keep things organized.

Why these three make a smart team

Carrots and onions complement each other both above and below ground. Carrots send down a deep taproot, while onions have shallower, fibrous roots. They’re not fighting for the exact same soil space.

Above ground, the smell of onions can help confuse carrot rust flies and other pests that target carrots. In return, carrots don’t bother onions at all, and their feathery tops allow light through.

Lettuce slips into the mix as a quick-growing, shallow-rooted crop that appreciates the partial shade created by the taller carrots and onions as they mature. In warming climates, this kind of shade-sharing is becoming more important. Many gardeners are now using taller crops to protect cool-season greens from heat waves and intense sun.

This trio is frequently used by gardeners who practice intensive planting and biointensive methods, which are discussed by organizations like Rodale Institute, known for research in organic and regenerative agriculture.

How to plant carrot, onion, and lettuce together

Think in strips or bands rather than rigid rows.

You might:

• Sow a band of carrot seeds about 3–4 inches wide
• Next to it, plant a band of onion sets or scallions
• Then, sow a band of lettuce seeds or transplant lettuce seedlings

Repeat this pattern across your bed. As the lettuce matures quickly, you can harvest it early, freeing up more space and light for the carrots and onions to continue growing. This staggered timing is another subtle example of companion planting: you’re not just mixing species, you’re blending different growth speeds.

Among all the examples of 3 companion planting examples for sustainable gardening, this one is especially friendly for small spaces and raised beds, and it’s easy to scale up or down.

More real examples of companion planting for sustainable gardening

Once you understand these three main templates, it’s easy to spot other real examples of companion planting that support sustainable gardening.

Here are a few more pairings and trios that fit the same principles:

Corn, beans, and sunflowers

A twist on the Three Sisters, this example of companion planting replaces squash with sunflowers. The sunflowers and corn both provide vertical structure, while beans climb either one. This creates a tall, dramatic planting that attracts pollinators and birds while giving you beans and corn.

Cabbage family with dill and calendula

Members of the cabbage family (kale, broccoli, cabbage, Brussels sprouts) often suffer from caterpillars and aphids. Planting dill nearby attracts beneficial insects like lacewings and parasitic wasps that prey on those pests. Calendula flowers draw in pollinators and more beneficial insects, and they add color.

This trio is one of the best examples of companion planting for integrated pest management, a strategy supported by university extension programs and outlined in resources linked by the Environmental Protection Agency as a way to reduce reliance on synthetic pesticides.

Peppers, oregano, and alyssum

Peppers enjoy warm, sunny conditions, and oregano makes a great groundcover herb around them. It helps shade the soil, reduces evaporation, and gives you a bonus kitchen herb. Sweet alyssum flowers attract hoverflies, whose larvae eat aphids. This is a compact, fragrant example of companion planting that fits well in containers or small beds.

Strawberries with thyme and borage

Strawberries can be paired with thyme as a low, spreading herb that fills gaps and helps protect the soil. Borage grows taller, with starry blue flowers that are highly attractive to pollinators and beneficial insects. Many gardeners also feel that borage improves the flavor and vigor of nearby strawberries.

These additional combinations may not be textbook examples of 3 companion planting examples for sustainable gardening in a single bed, but they follow the same pattern: mix plant heights, root depths, and functions (food, flowers, herbs) to create a more balanced mini-ecosystem.

How companion planting supports sustainable gardening in 2024–2025

Modern sustainable gardening is all about working with nature instead of constantly fighting it. That’s where these examples of 3 companion planting examples for sustainable gardening really shine.

Here’s how they support a more sustainable approach:

• Reduced chemical inputs: By using scent, diversity, and beneficial insects, you can often cut back on pesticides and sometimes even lower fertilizer use.
• Better soil health: Combinations like beans with corn (in the Three Sisters) help support soil fertility over time. Mixed root systems also improve soil structure.
• Water-wise gardening: Squash shading the soil, oregano covering bare ground, and lettuce growing in the shade of taller crops are all real examples of using plants to reduce evaporation and protect soil moisture.
• Biodiversity: Instead of long rows of a single crop, these examples of 3 companion planting examples for sustainable gardening encourage mixed plantings that support more insects, birds, and soil life.

Organizations like the USDA and research groups focused on agroecology consistently highlight diversity and soil protection as keys to resilient food systems. Companion planting is simply the home-gardener version of those same ideas.

FAQ: Common questions about companion planting examples

What are some easy examples of 3 companion planting examples for sustainable gardening for beginners?

Three of the easiest are:

• Corn, pole beans, and squash (the Three Sisters)
• Tomatoes, basil, and marigolds in a single bed or large container
• Carrots, onions, and lettuce in a cool-season bed

These examples include different plant heights and root systems, and they’re forgiving if your spacing isn’t perfect.

Can you give an example of a bad companion planting combination to avoid?

A classic example of a poor pairing is fennel with almost anything else. Fennel tends to inhibit the growth of many nearby plants, so it’s usually grown in its own space. Another tricky match is tall sunflowers shading small, sun-loving herbs that need full light. Not every plant wants a roommate.

Do these companion planting examples really reduce pests?

They can help, but they’re not magic. Real examples of companion planting, like tomatoes with basil and marigolds or cabbage with dill and calendula, support beneficial insects and can confuse or deter some pests. For serious infestations, though, you may still need additional organic controls. Companion planting is one tool in a broader integrated pest management approach.

Are there scientific studies behind these examples, or is it all folklore?

It’s a mix. Some relationships, like legumes fixing nitrogen or marigolds affecting certain nematodes, are well-documented in agricultural research. Others, like flavor improvements from specific herb pairings, are more observational. Universities and agricultural extensions (linked through sites like USDA NIFA) continue to study plant interactions, and the trend in 2024–2025 leans strongly toward encouraging plant diversity as a low-risk, high-benefit practice.

How can I start using these examples of companion planting in a very small space?

Think in mini trios. In a single large container, you might grow:

• One tomato plant with a basil plant and a border of marigolds
• A pepper plant with oregano and alyssum

Even on a balcony, these small-scale examples of 3 companion planting examples for sustainable gardening can bring you better pollination, some natural pest control, and a more interesting, productive container garden.

If you treat these examples of 3 companion planting examples for sustainable gardening as flexible templates rather than rigid rules, you’ll quickly gain confidence. Start with one trio this season, observe what happens, and adjust next year. That’s how gardeners have been refining these combinations for generations.