25 Best (and 7 Worst) Companion Plants for Tomatoes

Companion planting involves growing certain plants near each other to help them absorb nutrients better, control pests, help with pollination, and boost their growth.

Experienced gardeners have found that some plants can protect tomatoes from insects and diseases, making them grow stronger, while some plants should not be planted too close.

Discover which herbs, flowers, and root vegetables are the perfect companions for tomatoes, and which ones should be kept away to ensure your tomatoes thrive.

What Are Companion Plants?

Companion plants are two different plant types that are grown close together. When they grow next to each other, they help each other out in a special relationship.

Sometimes, one plant type is used as a companion to help the main crop plant grow better and stay healthy.

Companion plants can also be planted one after another (called succession planting). This type of gardening goes by a few names like interplanting, intercropping, or polyculture gardening.

What Are the Benefits of Planting Companions?

Lots of companion plants offer multiple benefits for tomato plants, such as repelling pests, loosening up the soil, and attracting helpful insects.

But before adding them, make sure they like growing in the same conditions as tomatoes: full sun and rich, well-drained soil.

Strong-smelling herbs may help shoo away insect pests, while flowers attract pollinating insects like bees. Tomatoes are self-pollinating, so they can make fruit without pollinators.

However, they’ll give you more tomatoes when pollinators are around.

Low-growing herbs act as a living mulch and work great planted with tomatoes in pots. Root crops like carrots help loosen and aerate the soil, allowing tomato roots to grow better. Some root crops also repel small pests.

Certain flowers even attract insects that are beneficial because they eat pests. In general, companion plants:

  • Use up available garden space efficiently
  • Improve the soil
  • Provide natural insect and disease control
  • Act as a living mulch to prevent weeds sustainably
  • Attract pollinators
  • Improve the health of one or both plants
  • Provide a second crop of edible veggies/fruits

A few companion plants, called trap crops, might have to be removed to protect the tomatoes. But more often, the companion plant gives you an extra harvest too! Think about what your tomatoes need most and try out different companions to see what works best.

Best Tomato Companion Plants to Repel Harmful Insects

Here are 5 Best Tomato Companion Plants to Repel Harmful Insects.

Calendula

The calendula flower has a strong, woody smell that repels big green hornworms. Its bright orange and yellow flowers are edible and make a tasty addition to salads. They also help shoo away rabbits, aphids, flea beetles, nematodes (tiny worms), and corn earworms.

Chives

Chives are a tasty, reusable herb that repels aphids, nematodes, and spider mites. When allowed to bloom, they attract pollinators like butterflies, bees, and beneficial wasps that eat pests.

Black-Eyed Peas

Black-eyed peas are a trap crop to lure stink bugs away from tomato plants. They produce a lot of peas, so you’ll likely still get a harvest.

Radishes

Radishes trap pesky flea beetles that make holes in tomato leaves, especially when the plants are young. Radishes grow shallow roots that don’t interfere with tomatoes, so plant them at the base. Flea beetles can ruin crops, so you may need to sacrifice your radish plants.

Sage

Sage is a wonderfully aromatic herb known for its robust, musky smell that keeps slugs, flea beetles, and spider mites away. When it blooms, it draws in helpful pollinators like butterflies and bumblebees.

However, it’s important to remember that sage prefers drier soil to tomatoes, so growing sage in pots is a good idea. This way, you can still place them near your tomato plants in the garden without worrying about overwatering your sage.

French Marigolds

French marigolds repel root-knot nematodes in the soil and grow nicely with tomatoes in containers. They also scare off tomato hornworms and aphids and lure other pests away as a trap crop. The cheerful orange and yellow flowers are edible and have a peppery taste for salads.

Nasturtiums

Nasturtiums act as a trap crop, attracting aphids and whiteflies away from tomatoes, which reduces the spread of fungal disease. They also attract pollinators and hoverflies that eat aphids. Both the leaves and flowers add a peppery flavor to dishes. The seed pods can be pickled as a caper substitute.

Best Tomato Companion Plants To Increase Beneficial Insects

Cilantro

When cilantro blooms, it attracts parasitic wasps that feed on big adult hornworms. This cool-season herb also repels the potato beetle pest early in the season. Fragrant and edible, cilantro is great for salsa. Note that cilantro likes cooler weather while tomatoes like warmth. Let cilantro bloom so the helpful wasps will come in summer.

Oregano

Blooming oregano attracts green lacewings, ferocious predators that eat many tomato pests. It also shelters ladybugs. The flowers attract pollinators, and the edible leaves are tasty herbs for Mediterranean dishes. Oregano needs drier soil than tomatoes, so grow it in pots around your garden.

Parsley

Flowering parsley attracts ladybugs, a top predator that eats aphids and hornworm eggs. Parsley is a living mulch for tomatoes and an edible herb for many dishes. Like cilantro, let parsley bloom when grown with warm-season tomatoes to attract helpful insects.

Best Tomato Companion Plants For Weed Control

Here are 5 best tomato companion plants for weed control.

Companion Plant How it Helps with Weed Control
Crimson Clover Clover Crimson clover makes an excellent living mulch for tomatoes and the whole garden. It can be tilled into the soil to replace used-up nitrogen. This plant is great for permaculture gardens and attracts pollinators, too.
White Clover White clover forms a dense mat that prevents weed seeds from germinating.
Buckwheat Buckwheat grows quickly and forms a thick vegetation cover that smothers weeds.
Rye Rye can be planted as a cover crop and tilled under before it goes to seed to prevent weeds.
Alfalfa Alfalfa’s thick roots and top growth outcompete weeds while fixing nitrogen in the soil.

Best Tomato Companion Plants To Increase Pollination

Here are 5 best tomato companion plants to increase pollination.

Companion Plant How it Increases Pollination
Lavender Lavender flowers are a favorite of bumble bees that buzz tomato flowers, releasing pollen to aid fertilization.
Sunflowers Sunflowers attract native bees, including bumble bees, to encourage tomato pollination.
Zinnias Zinnias bring more color to a garden than almost any other bloom, flocking pollinators and predators.
Borage Borage attracts bumble bees and honeybees to the garden.
Bee Balm The red flowers of bee balm are highly attractive to many types of bees and pollinating insects.

Best Tomato Companion Plants To Improve Tomato Health

Here are 5 best tomato companion plants that can improve tomato health.

1. Asparagus

Asparagus releases a toxic compound to root-knot nematodes, preventing tomato issues like yellowing leaves, stunted growth, and wilting. It also makes a natural fungicide that helps stop early blight and botrytis diseases. Plus, tomatoes produce solanine, which repels the asparagus beetle, making a perfect pair!

2. Basil

Basil helps tomatoes grow bigger roots for more fruit production. Its strong scent comes from oils that repel pests like aphids, whiteflies, and hornworms. The fragrance masks tomato plants, making them harder for pests to find and lay eggs on.

3. Borage

Borage provides vitamins, minerals and other nutrients that improve soil for healthier tomatoes. It also repels hornworms, attracts bees, and can act as a living mulch around tomato plants.

4. Carrots

Carrots help loosen and aerate soil around tomato roots so they grow better. Shorter carrot varieties work best, as longer ones may not fully develop. But either way, you’ll still get edible carrots!

5. Garlic

Garlic’s strong scent and natural bacteria/fungus-fighting compounds make it awesome for repelling pests and preventing soil diseases around tomatoes.

Best Plants To Grow In Containers With Tomatoes

Sweet Alyssum

Sweet alyssum is a popular filler/groundcover plant that grows nicely potted with tomatoes. Its flowers attract predators like parasitic wasps that eat pests like aphids.

Thyme

Thyme is a fragrant, edible, low-growing herb perfect for planting in tomato pots. It comes in varieties like lemon-scented. Its natural oils repel ants, aphids, armyworms, and other pests. Blooms attract native pollinators and wasps that eat hornworms.

Worst Tomato Companion Plants

Here are 7 type of worst tomato companion plants. These are

Plant Incompatibility with Tomatoes
Cabbage Family Crops (broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, kohlrabi) Veggies like broccoli, Brussels sprouts, cabbage, cauliflower, collard greens, ornamental kale, and kohlrabi are all relatives that stunt tomato plant growth when grown nearby.
Fennel This herb releases substances from its roots that inhibit and prevent proper tomato plant growth.
Dill Once dill plants get older and mature, they actually damage and stunt the growth of nearby tomato roots.
Nightshade Family (eggplants, peppers, potatoes) Eggplants, peppers, and potatoes can all get the same diseases as tomatoes – early blight and late blight. Avoid planting these next to each other. Also, rotate replanting nightshades in the same spot only every 3 years. Tomato hornworms (scientific name Manduca quinquemaculata) are very destructive pests that chomp through leaves and fruit on all these nightshade plants.
Cucumbers Both cucumbers and tomatoes can spread viruses and blights like cucumber mosaic virus and phytophthora blight to each other when planted together. You can still grow cucumbers with tomatoes, but only if you’re transplanting started tomato plants, not growing them from seeds in the garden.
Sweet Corn Sweet corn attracts corn earworms, which are actually the same pest as the tomato fruitworm (scientific name Helicoverpa zea). It’s best to avoid planting crops together that are prone to the same insect pests.
Rosemary This herb uses up a lot of the same nutrients in the soil that tomatoes need to thrive. Rosemary also prefers different soil and growing conditions compared to tomatoes.

Tips For Companion Planting

Successful companion planting requires you to know each plant’s light, water, and nutrition needs – you don’t want them competing for resources.

  1. Grow heat-sensitive plants in the shade of tomatoes.
  2. Plant nitrogen-replenishing plants like beans and peas after heavy feeders like tomatoes that deplete the soil.
  3. Use big leafy spreaders like zucchini and pumpkins to protect shallow-rooted plants.
  4. Avoid pairing a plant that likes dry soil, like rosemary, with one that needs consistently moist soil.
  5. Don’t plant together or stagger crops that attract the same pests, especially underground overwintering ones. Tomatoes, peppers, and eggplants all get hornworms.
  6. Always have a section in your veggie garden just for pollinator-attracting flowers.
  7. Use annual plant companions first. Good crop rotation means perennials will need digging up/removing each year.

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