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Companion Planting4 min readFebruary 28, 2026

Best Companion Plants for Tomatoes (What to Grow Nearby)

The best companion plants for tomatoes include basil, carrots, marigolds, and parsley. Learn what to plant near tomatoes and what to keep away for a healthier garden.

Tomatoes are the star of most vegetable gardens, but they grow even better with the right neighbors. Companion planting with tomatoes can help improve flavor, repel pests, and maximize garden space.

Here are the best plants to grow alongside your tomatoes, plus what to avoid planting nearby.

Best Companion Plants for Tomatoes

These companions earn their place through pest control, efficient use of space, or both. Spacing them correctly keeps them from competing with your tomatoes for sun and nutrients.

Companion spacing at a glance
Basil
12-18 inches from tomato stems
Carrots
6-8 inches from tomato base
Marigolds
Around the perimeter of tomato beds
Parsley
8-12 inches from tomatoes
Chives & onions
Clusters 6 inches from tomato stems
Lettuce
Interplant between young tomato plants

Basil

Why it works: May repel hornworm moths and aphids. Many gardeners swear their tomatoes taste better when basil grows nearby.

Carrots

Why it works: Root vegetables use different soil nutrients and won't compete with tomatoes. Carrots can grow in the shade of tomato plants.

Marigolds

Why it works: French marigolds suppress root-knot nematodes and their scent may confuse pest insects.

Parsley

Why it works: Attracts beneficial insects that prey on tomato pests. Doesn't compete for nutrients.

Chives & Onions

Why it works: Strong scent may deter aphids and other soft-bodied insects. Take up minimal space.

Lettuce

Why it works: Fast-growing ground cover that's harvested before tomatoes need full space. Shallow roots won't compete.

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What NOT to Plant Near Tomatoes

Some plants compete with tomatoes or attract the same pests and diseases. Avoid these companions:

  • Fennel: Releases chemicals that inhibit tomato growth
  • Brassicas (cabbage, broccoli): Heavy feeders that compete for nutrients
  • Corn: Shares the corn earworm pest, which also attacks tomatoes
  • Potatoes: Both are nightshades and share diseases like late blight
  • Walnut trees: Release juglone, which is toxic to tomatoes

Companion Planting Layout Tips

Pro planting tips

Give tomatoes priority — they need full sun and good air circulation. Choose companions that mature quickly so you can harvest them before tomatoes get large, use vertical space for climbing companions like pole beans, and consider bloom times: marigolds and nasturtiums flower all season.

Natural Pest Control Benefits

The best companion plants offer natural pest protection:

Companion PlantPests It Helps ControlHow It Works
BasilHornworms, aphidsStrong scent may confuse pests
MarigoldsNematodes, aphidsRoot chemicals, scent deterrent
NasturtiumsAphids, cucumber beetlesTrap crop — attracts pests away
ChivesAphids, spider mitesSulfur compounds repel insects

Frequently Asked Questions

Is basil really the best companion for tomatoes?

Yes, basil is probably the #1 tomato companion. It may repel hornworm moths and aphids, and many gardeners report better-tasting tomatoes when basil grows nearby. The chemical compounds in basil may enhance tomato flavor.

Can you plant peppers next to tomatoes?

You can, but it's not ideal. They're both nightshades, so they share pests and diseases. If one gets early blight or hornworms, the other will too. If you plant them together, watch carefully for signs of disease and space them well apart. See best companion plants for peppers for better neighbors.

Do marigolds really help tomatoes?

French marigolds (Tagetes patula) do have proven benefits — they suppress root-knot nematodes in the soil and their strong scent may confuse some flying pests. Plant them around the perimeter of your tomato bed. African marigolds are less effective.

How close can I plant companions to tomatoes?

It depends on the plant. Small herbs like basil can go 12-18 inches away. Carrots and radishes can be 6-8 inches from the stem. Always ensure tomatoes get full sun and good air circulation — don't crowd them.

Plan the rest of your tomato patch with these guides: