Ivy WhitmanBy Ivy Whitman

A companion vegetable planting guide chart shows you which crops grow well side by side and which ones should stay apart. Used well, it helps you plan bed layouts, space plants correctly and avoid the common pairings that stunt growth or invite pests. This guide explains how to read a companion chart, build your own version for your garden, and use it alongside spacing and timing so the chart actually improves your harvest.

What a Companion Planting Chart Actually Tells You

A companion chart is a grid or list that pairs vegetables with their likely partners (good neighbors), their likely rivals (plants to keep apart), and sometimes notes on herbs or flowers that attract beneficial insects. Most charts are built from long-standing gardening practice and extension-style observations rather than controlled trials, so treat each pairing as a starting point. Some effects are well documented, such as legumes adding nitrogen to the soil. Others, like a specific herb supposedly repelling a specific pest, vary a lot with climate, soil and pest pressure.

Shopping for one? See our guide: Marigold Seeds for Companion Planting: 8 Best Picks for Vegetable Gardens (2026).

Good charts separate three kinds of relationships: nutrient or structural benefits (a tall crop providing afternoon shade, a legume feeding a heavy feeder), pest and disease relationships (a strong-smelling herb confusing pests, a trap crop drawing insects away), and competition (two crops with similar root depths and nutrient demands fighting over the same soil). Knowing which type of relationship a chart entry describes helps you judge how much to rely on it.

How to Build Your Own Companion Planting Chart

A printed chart is useful, but a chart tailored to your beds is more useful. Work through these steps once per season.

Step 1: List the crops you actually grow

Start with your planned crops for the season, not every vegetable you have ever considered. A list of 12 to 20 crops is manageable. Group them by family too, since crops in the same family (such as tomatoes, peppers, eggplant and potatoes in the nightshade family) share pests and diseases and usually should not be planted in the same spot year after year.

Step 2: Note the growth habit of each crop

Record height, root depth, spread and harvest timing. Pair tall, upright crops with shade-tolerant crops that sit to their north in the Northern Hemisphere so the tall plants do not shade the short ones. Pair fast-maturing crops like radishes or lettuce with slow crops like brassicas or winter squash, so the space gets used twice.

Step 3: Mark good, neutral and avoid pairings

Use a simple three-color or three-symbol system. A green check means a well-supported good pairing. A yellow dot means neutral or situational. A red X means keep apart, usually because of shared pests, allelopathy claims or heavy competition. Keep notes on why, because the reason tells you when a rule can be bent.

Step 4: Test the chart against your bed

Sketch your bed or plot to scale, then place crops on the sketch. Check spacing and sun exposure before you dig. A chart pairing that looks perfect on paper can fail if two plants both need full sun and one ends up in deep shade from a fence.

Reading the Chart Alongside Spacing and Timing

Companion pairings only work if the plants have room. Crowding creates the same problems companion planting is meant to prevent, including poor airflow, fungal disease and competition for water and nutrients. Use these typical spacing figures as a baseline, and always check your seed packet, since varieties differ.

Crop Plant spacing Common good companions Keep apart from
Tomato (indeterminate) 18 to 24 inches Basil, parsley, carrots, marigolds Potatoes, fennel, brassicas
Carrot 2 to 3 inches (thinned) Onions, leeks, lettuce, rosemary Dill, parsnip (shared pests)
Lettuce 6 to 8 inches Carrots, radishes, strawberries Cabbage family in some charts (mixed evidence)
Bush beans 3 to 4 inches Carrots, cucumbers, corn, potatoes Onions, garlic, leeks
Cabbage 12 to 18 inches Dill, chamomile, aromatic herbs, onions Strawberries, tomatoes
Cucumber 12 to 18 inches (trellised) Beans, peas, radishes, sunflowers Potatoes, aromatic herbs like sage
Onion 4 to 6 inches Carrots, beets, lettuce, strawberries Beans, peas

Timing matters as much as placement. A radish sown between two slow-growing tomatoes is a classic space-saving use, because it is harvested before the tomatoes need the room. Plan successions so that a companion that finishes early gives way to a crop that benefits from the cover it leaves behind.

Practical Checklist for Using a Companion Chart

  1. Confirm your last frost date and sow or transplant within the right window for each crop.
  2. Check the sun exposure of each bed, noting morning and afternoon shade.
  3. Sketch the bed to scale and place tall crops on the north side (or the side that avoids shading the rest).
  4. Group crops by family and rotate them so the same family does not return to the same bed for at least three years where possible.
  5. Mark good, neutral and avoid pairings on your sketch.
  6. Leave walkways of about 18 inches in raised beds, or follow the spacing your layout method uses.
  7. Label everything and keep a garden journal so you can see what worked next season.

Common Mistakes to Avoid

  • Treating every pairing as a guarantee. Companion effects are often modest and depend on pest pressure, soil and weather. Use the chart to narrow your choices, not to replace observation.
  • Ignoring spacing. Two good companions planted too close still compete and crowd each other.
  • Forgetting plant families. A pairing can look good while both crops share a soil-borne disease that will build up season after season.
  • Pairing crops with different water needs. A thirsty crop next to a drought-tolerant herb often leads to overwatering the herb or underwatering the vegetable.
  • Letting herbs take over. Mints and some other herbs spread aggressively. Keep them in containers or a dedicated bed.
  • Planting for pests you do not have. Focus on the pests you actually see in your garden, and watch for them over a full season before changing your layout.

Tips for Getting the Most from Your Chart

  • Update your chart at the end of each season with notes on what grew well, what struggled and which pests showed up.
  • Use flowers such as calendula and alyssum at the edges of beds to draw pollinators and predatory insects, which supports the whole bed.
  • Pair legumes like bush beans or peas with heavy feeders such as corn or cabbage, since legumes host nitrogen-fixing bacteria that can benefit neighboring plants when residue breaks down.
  • Keep a few bare patches or mulched paths so you can reach plants without stepping into the soil.
  • If a chart says two plants are incompatible, try a small test in one part of the garden before abandoning the pairing entirely.

FAQ

Is a companion planting chart based on scientific evidence?

Some entries are well supported, such as legumes fixing nitrogen, while others come from traditional practice and anecdotal observation. Extension services and university research offer more detail on specific pairings, and you can check those sources when a claim matters to your plan.

Do I need a companion chart for container gardening?

A chart is still useful in containers, mainly for spacing, sun needs and avoiding plants that compete hard for water. Container size limits how many companions fit, so focus on pairing crops with similar watering needs.

Can companion planting replace pest control?

No. Companion planting can reduce pest pressure in some cases, but it works best alongside regular inspection, crop rotation, healthy soil and targeted control when needed.

How often should I rotate crops?

Rotate crop families so the same family does not return to the same bed for at least three years where possible. This reduces the buildup of soil-borne diseases and pests specific to that family.

What is the most reliable companion pairing for beginners?

Beans or peas with carrots, or tomatoes with basil, are frequently recommended starting pairings because they combine good spacing, similar growing conditions and widely reported benefits. Start with a few pairings you can observe clearly.

Should I plant companions in the same hole?

Usually not. Give each plant its own spacing so roots and airflow are not compromised. Companion benefits come from arrangement and timing, not crowding.

Do flowers really help vegetables?

Flowers such as alyssum, calendula and dill can attract pollinators and beneficial insects that prey on pests. The effect depends on local insect populations, so plant them early in the season and watch what visits.

How do I know if a pairing is working?

Track plant health, pest counts, yield and growth rate in a journal. Compare beds with and without a pairing over at least one full season before deciding whether to keep it.

Conclusion

A companion vegetable planting guide chart is most useful when you treat it as a planning tool rather than a rulebook. Build a chart around the crops you grow, test it against your sun, spacing and timing, and record what happens. Over a few seasons, your own notes will become the most accurate companion chart you own.

Ivy Whitman

About Ivy Whitman

Ivy puts together our vegetable & edible gardening guides, digging through specifications, manufacturer details and owner reviews so you don't have to.