The 12 Best Tomato Companion Plants For Your Best Crop Ever

Companion planting is the centuries-old practice of pairing plants in the garden that benefit one another. Our gardens function as interconnected communities, with different plants providing unique services. Some plants attract beneficial insects, others ward off pests, while some enhance soil health. Anyone who’s grown tomatoes knows they are heavy feeders, and often plagued by foliar diseases and a diversity of insect pests. They certainly stand to benefit from tomato companion plants that promote healthier plants and increased yields. 

Considerations For Choosing Tomato Companion Plants

When selecting companion plants to grow among tomatoes, consider the common pest problems for your area. Identify plants that can be used as trap crops or deterrents to help you limit outbreaks. Plant plenty of nectar-rich flowers in and near your vegetables to enhance beneficial insect populations including pollinators. Finally, growing cover crops can help you build soil while managing weeds and other pests.

A great many companion planting strategies have been passed down from one generation to the next, but not all are truly effective. The tomato companion plants listed here have been proven through scientific testing. They are organized here based on the services they provide tomatoes and other neighboring plants.  

Tomato Companion Plants To Use As Trap Crops

Trap crops attract pests away from desirable plants such as food crops or ornamental plantings. They are used to manage pests that are regular and destructive in most years. Since we expect these pest outbreaks, we can plan for them by planting trap crops that are more attractive to the pest than the main crop. Once the pest arrives on the trap crop, we can treat them in place or remove the plants, pests and all, for disposal. Note that planting times listed below are based specifically on the plants' use as trap crops.  

Radish

• Botanical Name: Raphanus sativus var. radicula
• Planting Time: 2-3 weeks prior to planting tomatoes

Radish plants are commonly planted around young tomato plants to trap flea beetles. These tiny black beetles chew holes in leaves and their larvae feed on roots. Flea beetles are particularly damaging to seedlings and can stunt young plants. Flea beetles feed on a variety of crops including tomatoes, peppers, and eggplants, however, they are most attracted to radishes. Plant radishes around the base of tomato plant to trap flea beetles, sowing seeds a few weeks prior to setting tomatoes.  

Cowpeas

• Botanical Name: Vigna unguiculata
• Planting Time: 2-3 weeks prior to planting tomatoes

Cowpeas (also called black-eyed) peas provide several ecosystem services in the garden. They can be planted as a groundcover or living mulch to reduce weeds and fix nitrogen in the soil, however, cowpeas can be allelopathic to seeds (preventing germination), so only use them alongside transplants or established plants. From a pest management standpoint, they make an excellent trap crop for Southern green stink bugs. For this purpose, you want to plant them a short distance away from tomatoes where you can collect and destroy the stinkbugs.  

Tomato Companion Plants To Deter Pests

While some companion plants are used to attract and trap pests, others are planted to deter pests. Companion plants with strong odors are used to confuse pests or mask the scent of crops so insect pests cannot find them. Other deterrents act by repelling insects and disease organisms. 

Thyme

• Botanical Name: Thymus vulgaris
• Planting Time: Late spring, after threat of frost has passed

Like many herbs, thyme leaves produce fragrant compounds that give plants a sharp taste and scent. Research has shown these compounds can be used to ward off insects, including yellowstriped armyworms, a common tomato pest. Thyme also makes a great living mulch around tomato plants, helping to suppress weeds, cool soils, and conserve soil moisture. Thyme is a perennial plant and can be transplanted to different areas of the garden as vegetable crops are rotated form one season to the next.

Hairy Vetch

• Botanical Name: Vica villosa
• Planting Time: Late fall for a winter cover crop

Hairy vetch is a cool-season legume commonly planted as a winter cover crop to fix nitrogen in the soil, improve soil structure, and reduce soil erosion. Hairy vetch has been show to suppress early blight and septoria leaf spot on tomatoes when planted as a winter cover crop prior to planting tomatoes. Sow seeds in autumn for winter cover. Plants grow rapidly in spring, smothering weeds and feeding the soil. Cut or mow plants in spring before they flower and allow the plant residues to remain on the soil surface to achieve disease suppression. Plant tomatoes through this residue, which also serves as mulch.

Basil

• Botanical Name: Ocimum basilicum
• Planting Time: Late spring, after threat of frost has passed

Basil is another strong-scented plant. The aroma masks the smell of tomatoes, working to deter thrips and other garden pests from finding your crop. This is important because thrips not only feed on tomato plants, but also transmit tomato spotted wilt virus which causes stunted growth and premature fruit drop. For effective companion planting, interplant basil between tomato plants. Basil is also known to deter aphids, spider mites, and whiteflies and reduce egg-laying by armyworms.

Tomato Companion Plants To Attract Beneficial Insects

Planting flowers to attract pollinators and other beneficial insects is a great way to diversify the garden and enhance natural pest control by predators and parasitoids. Parasitoids are non-stinging wasps, flies, and other insects that develop on or in a host, eventually killing it. If you’ve ever seen a tomato hornworm covered with cottony white protrusions, you’ve seen the cocoons of a parasitoid. Parasitoids and insect predators such as lacewings, syrphid (flower or hover) flies, and lady beetles feed on nectar as well as garden pests. Attract these beneficial insects by planting nectar-rich flowers in and around the garden. 

Dill

• Botanical Name: Anethum graveolens
• Planting Time: Late spring, after threat of frost has passed

Dill is a fabulous garden plant, providing flavorful foliage and seeds for kitchen use, as well as vibrant blooms beloved by predatory wasps, lacewings, and syrphid flies. These predators feed on aphids, whiteflies, insect eggs, and other pests. The blooms also attract the parasitoid wasp that lays its eggs on tomato hornworms. If that weren’t enough, dill serves as a host plant to larvae of the gorgeous black swallowtail butterfly.

Sweet Alyssum

• Botanical Name: Lobularia maritima
• Planting Time: Late spring, after threat of frost has passed

Sweet alyssum is as lovely as it is useful, producing an abundance of tiny, nectar-rich flowers—a great food source for parasitoids, lacewings, syrphid flies, and lady beetles. These beneficial insects feed on aphids, insect eggs, and other garden pests. Sweet alyssum is a low-growing annual perfect for tucking beneath tall plants like tomato or lining the edges of planting beds. It has demonstrated positive impacts in aphid management. 

Cilantro

• Botanical Name: Coriandrum sativum
• Planting Time: Early spring and fall

Cilantro plants begin to bolt when the weather heats up, sending out a spray of white flowers that attract a variety of beneficial insects. Cilantro flowers are very small, perfect for attracting parasitoids and predators that feed on garden pests like Colorado potato beetle and tomato fruitworms. Sow cilantro seeds at intervals in spring and late summer to provide a continuous supply of tasty foliage followed by the beneficial blooms.  

Oregano

• Botanical Name: Coriandrum sativum
• Planting Time: Late spring, after threat of frost has passed

The nectaries of oregano blooms are a little larger than those of cilantro and sweet alyssum and thus attract larger insects such as honeybees, native bees, and syrphid (flower) flies. The larvae of syrphid flies, also called flower or hover flies, feed on soft-bodied insects like aphids, white flies, and small caterpillars, as well as insect eggs. Oregano makes a great groundcover or edger for garden beds. 

Tomato Companion Plants That Work From The Ground Up

Many companion plants make their greatest impact at or below the soil surface. Some serve as groundcovers or living mulches to suppress weeds and retain soil moisture. Others are used as winter cover crops to protect garden beds from erosion. Many of these plants provide additional
benefits to garden communities. 

White Clover

• Botanical Name: Trifolium repens
• Planting Time: Fall, late winter, or early spring

White clover is a low-growing perennial commonly used as a living mulch beneath fruits and vegetables. White clover provides a variety of soil-enhancing services. As a member of the legume family, clovers fix nitrogen in the soil, making it available to nearby plants. They help to stabilize soils
and are very effective at suppressing weeds. White clover plants also produce a flush of blooms that attract beneficial insects, including native bee species.  

Winter Rye

• Botanical Name: Secale cereale
• Planting Time: Fall

Winter rye is planted as a winter cover crop in fall to protect soil over the winter. Plants put on a flush of growth in early spring and are cut back before they set seed. The residue can be left in place on the soil surface or tilled under, providing an abundance of organic matter for soil building. Winter rye residues also release allelopathic chemicals into the soil that restrict the germination and growth of seeds. These chemicals do not harm transplanted tomato seedlings (or those of other vegetable transplants), only seeds. By planting tomatoes among winter rye residues, you can take advantage of this weed suppression. For the best results, leave winter rye residues on top of the soil surface. 

Crimson Clover

• Botanical Name: Trifolium incarnatum
• Planting Time: Fall, late winter, or early spring

Crimson clover is a cool-season annual in the legume family that excels at fixing nitrogen in the soil. Grow as a winter cover crop, mowing or cutting plants in spring when they come into bloom. Crimson clover can also be grown as a living mulch around tomato plants. Although the flowers are quite lovely and attract native bees and minute pirate bugs (an insect that feeds on thrips, spider mites, and aphids), plants can become weedy if allowed to set seed. As a living mulch, cut crimson clover back several times per season before the flowers set seed. Residues can be left on the soil surface.