Tomatoes are one of the most popular and rewarding crops to grow in a home garden. They are versatile, delicious, and nutritious.
However, they can also be susceptible to various pests and diseases that can reduce their yield and quality. That’s why companion planting is a smart strategy to help your tomatoes thrive.
Companion planting is the practice of growing different plants together that benefit each other in some way, such as repelling pests, attracting pollinators, improving soil health, or enhancing flavor.
Related: Tomato Plant Seeds – Where to Buy & How to Plant Them (2023)
17 proven effective companion plants for tomatoes
In this blog post, we will introduce you to 17 proven effective companion plants for tomatoes that you can try in your garden. These plants are based on scientific evidence, anecdotal reports, and common sense. We will also explain how each plant helps your tomatoes and how to plant them together for optimal results.
Basil
Basil helps to repel pests that can damage tomatoes such as aphids, whiteflies, thrips, and the tomato hornworm.
Basil also enhances the flavor of tomatoes by producing volatile oils that are absorbed by the tomato plants. This makes the tomatoes more aromatic and tasty.
Borage
Borage can deter tomato hornworms, a common pest that feeds on tomato leaves and fruits. Borage also attracts desirable insects such as bees and tiny wasps that pollinate the flowers and control other pests.
Borage can improve the flavor and growth of tomatoes by adding trace minerals to the soil such as potassium, calcium, and vitamin C.
Calendula
Calendula, also known as pot marigold, is a great companion plant for tomatoes because it repels pests, attracts pollinators, and improves soil health. Calendula repels insects that can harm tomato plants such as aphids, whiteflies, hornworms, and nematodes. The strong scent of calendula flowers and leaves confuses and deters these pests from finding their host plants.
Calendula also attracts beneficial insects that can help tomato plants such as bees, butterflies, ladybugs, and hoverflies. These insects pollinate the flowers and can even help to eat the pests.
Calendula improves soil health by adding organic matter, nitrogen, and phosphorus. Calendula roots also help break up compacted soil and improve drainage. Calendula flowers can be used as green manure or mulch to enrich the soil and suppress weeds.
Carrots
Carrots have a strong scent that can repel pests such as tomato hornworms, aphids, and carrot flies. Carrots can also help to loosen the soil and improve drainage for tomatoes, which prefer well-drained soil. They grow well with tomatoes as long as they are harvested before they compete for space.
Carrots can be harvested at different times than tomatoes, which reduces competition for nutrients and space.
Carrots can enhance the flavor of tomatoes by attracting beneficial insects such as parasitic wasps and bumble bees that pollinate the flowers and control pests. Some of the best varieties of carrots to plant with tomatoes are Royal Chantenay and Danvers 126. Carrots should be planted about 3 inches apart from tomatoes and thinned regularly to avoid overcrowding.
Chives
Chives are one of the best companion plants for tomatoes because they contain sulfur-based compounds that deter aphids, spider mites, and other insects that feed on tomato plants. Chives also attract beneficial insects and pollinators such as bees and hoverflies that can help with tomato pollination and pest control.
Garlic
Garlic can repel spider mites, aphids, and other pests that can damage tomato plants. Garlic can also improve the growth and flavor of tomatoes by enhancing the soil with its strong aroma and nutrients.
Garlic can attract beneficial insects such as bumble bees and ladybugs that can pollinate and protect tomato plants.
Lettuce
Tomatoes and lettuce have different nutrient needs and do not compete for the same resources in the soil. Tomatoes are heavy feeders that need a lot of nitrogen, phosphorus, and potassium, while lettuce is a light feeder that needs more calcium and magnesium. By planting them together, you can optimize the use of fertilizers and avoid nutrient imbalances.
Lettuce is a proven effective companion plant for tomatoes because it can improve the growth, flavor, and pest resistance of both crops.
Mint
Mint can help improve the vigor and growth of tomato plants by providing them with essential nutrients and minerals while improving the flavor of tomato fruits by imparting a subtle minty aroma.
Mint can also help deter pests like tomato hornworms, aphids, whiteflies, and spider mites that can damage tomato plants and reduce their yield.
Mint can help attract beneficial insects like bees, butterflies, and ladybugs that can pollinate tomato flowers and control pest populations.
Nasturtiums
Nasturtiums attract beneficial insects such as bees and ladybugs that help with pollination and pest control while repelling harmful insects such as aphids and whiteflies that can damage tomato plants.
Oregano
Oregano can repel some of the common pests that attack tomato plants, such as tomato hornworms, aphids, and whiteflies. Oregano’s strong scent and essential oils can deter these insects from feeding on your tomatoes or laying eggs on them. Oregano can also attract beneficial insects such as parasitic wasps, ladybugs, and bees.
Oregano helps to improve the growth and flavor of your tomatoes by providing them with nitrogen and other nutrients. Oregano is a nitrogen-fixing plant that can enrich the soil and help your tomatoes produce larger fruits. Oregano can also enhance the taste of your tomatoes by imparting some of their savory aromas to them.
Parsley
Parsley attracts beneficial insects that prey on tomato pests such as ladybugs, hoverflies, and braconid wasps. These insects can help control aphids, hornworms, gypsy moths, and armyworms that can damage tomato plants and fruits.
Parsley helps to provide nitrogen to the soil which tomatoes need for healthy growth and fruit production. Parsley can also help suppress weeds that compete with tomatoes for nutrients and water.
Parsley also aids in improving the taste and aroma of tomatoes by releasing volatile oils that may influence the chemical composition of tomato fruits.
Peppers
Peppers and tomatoes can provide mutual protection from pests and diseases, as they attract different beneficial insects and repel harmful ones. For example, peppers can deter tomato hornworms, while tomatoes can ward off pepper weevils.
Peppers and tomatoes can enhance each other’s flavor and yield, as they release chemicals that stimulate plant growth and fruit production. Peppers can also benefit from the shade and windbreak that tomatoes provide, especially in hot and dry climates.
Petunias
Petunias repel pests that can damage tomato plants, such as asparagus beetles, leafhoppers, aphids, and tomato worms.
Petunias attract pollinators that can boost the fruit production of tomato plants, such as bees, butterflies, and hummingbirds. Petunias produce sweet nectar that lures these beneficial insects to your garden, where they can also pollinate your tomato flowers and increase your yield.
Petunias act as a ground cover that can help retain soil moisture and prevent weeds from growing around your tomato plants. Petunias have a low-growing habit that can fill in the gaps between your tomato plants and create a dense carpet of blooms. This can reduce water evaporation and weed competition which can improve the health and vigor of your tomato plants.
Sage
Sage can deter some common tomato pests, such as flea beetles, hornworms, and spittlebugs. These insects can damage the leaves, stems, and fruits of tomato plants, reducing their quality and quantity. Sage has a strong scent that can confuse or repel these pests, making them less likely to attack the tomatoes.
Planting sage near tomatoes can also attract beneficial insects, such as bees and hoverflies that can pollinate the flowers and increase the fruit yield.
Sage can release volatile compounds that can enhance the taste and aroma of tomatoes by increasing their sugar and acid content.
Spinach
Spinach can lure away some pests that feed on tomatoes, such as aphids, beetles, and hornworms. Spinach can also attract pollinators such as bees and butterflies that can help tomatoes set more fruits. Additionally, spinach can deter some diseases that affect tomatoes, such as fusarium wilt and verticillium wilt.
Spinach has deep roots that can loosen the soil and improve its drainage and aeration. Spinach can also add organic matter and nitrogen to the soil when it decomposes after harvesting. Nitrogen is an essential nutrient for tomatoes that promotes their growth and fruiting.
Thyme
Thyme can repel pests that attack tomato plants, such as tomato hornworms, yellow-striped armyworms, aphids, and whiteflies. Thyme has a strong scent that discourages these insects from laying eggs or feeding on tomato leaves and fruits.
Thyme can also attract beneficial insects that prey on tomato pests, such as ladybugs, lacewings, and parasitic wasps.
Thyme can enhance the flavor and quality of tomatoes, as it contains volatile oils that can be absorbed by the tomato plants through their roots or leaves. Thyme can also improve soil health and fertility by adding organic matter and nutrients to it.
Thyme can act as a living mulch for tomatoes, as it grows low to the ground and covers the soil surface. This can help conserve soil moisture, prevent weed growth, moderate soil temperature, and reduce soil erosion.
Beans
Beans help to add nitrogen into the soil which tomatoes need for healthy growth and fruit production. Beans can also attract bumblebees which are excellent pollinators for tomato flowers. These beans can also act as a trap crop for some pests that would otherwise attack tomatoes, such as southern green stink bugs and harlequin bugs.
FAQ
Will tomato plants come back?
Tomato plants are annuals, which means they complete their life cycle in one growing season and do not come back the next year.
How often should tomato plants be fertilized?
Tomato plants are heavy feeders that require regular fertilization to produce healthy fruits. The frequency of fertilizing depends on the type of soil, the size of the plants, and the stage of growth.
A general rule of thumb is to apply a balanced fertilizer (such as 10-10-10) every two to four weeks during the growing season, starting when the first fruits are set.
How many tomato plants per container?
Generally, one tomato plant per container is recommended, especially for large varieties that need more space and support.
Smaller or dwarf varieties can be planted two or three per container, as long as they are spaced evenly and given adequate water and fertilizer.
How often tomato plants should be watered?
A general rule of thumb is to water tomato plants once every two to three days during the summer and once a week during the cooler months.
Will tomato plants cross-pollinate?
Tomato plants are self-pollinating, which means that they have both male and female parts in the same flower. However, cross-pollination can occur when pollen from one plant is transferred to another by insects, wind, or human intervention.
