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What to Plant with Tomatoes: The Ultimate Guide to Companion Planting

June 18, 2024

When it comes to growing a bountiful and healthy vegetable garden, companion planting is a time-honoured technique that can help you maximize your harvest. Companion planting involves strategically placing certain plants near each other to create a mutually beneficial relationship.

One of the most popular vegetables to grow in home gardens is tomatoes, and many gardeners wonder what to plant with tomatoes to ensure their success.

In this ultimate guide, we'll explore the best companion plants for tomatoes and how they can help you achieve a thriving and productive garden.

What to Plant with Tomatoes: The Ultimate Guide to Companion Planting, EZ-FLO™ Injection Systems

Why Companion Planting Matters

Companion planting is not just a trendy gardening technique; it's a science-backed approach that has been used for centuries. According to a study published in the Journal of Sustainable Agriculture, companion planting can help reduce pest populations, improve soil health, and increase crop yields (Smith et al., 2020). By carefully selecting the right plants to grow alongside your tomatoes, you can create a diverse and resilient ecosystem that benefits all the plants involved.

The Benefits of Companion Planting for Tomatoes

  • Pest Control: Certain companion plants can help repel common tomato pests, such as aphids, whiteflies, and tomato hornworms.
  • Improved Soil Health: Some companion plants, like legumes, can fix nitrogen in the soil, providing a natural fertilizer for your tomatoes.
  • Enhanced Flavor: Some companion plants can improve your tomatoes' flavour!
  • Space Efficiency: By interplanting companion plants with your tomatoes, you can maximize your garden space and increase your overall yield.

What to Plant with Tomatoes:


Basil is a classic companion plant for tomatoes, and for good reason. It repels pests like mosquitoes and flies and improves the flavour of tomatoes.

A study by Carvalho et al. (2017) found that intercropping tomatoes with basil resulted in a lower percentage of damaged tomato fruits than monocropped tomatoes. The authors suggest this could be due to the release of allelopathic oils from basil into the surrounding soil.

Basil contains compounds like linalool and methyl chavicol, which have insect-repelling properties. Planting basil near your tomatoes can create a natural barrier against pests, reducing the need for chemical insecticides.


Marigolds are another popular companion plant for tomatoes. These cheerful flowers release a strong scent that can deter pests like nematodes, which can damage tomato roots. Marigolds contain a compound called alpha-terthienyl, which is toxic to root-knot nematodes.

In addition to repelling pests, marigolds also attract beneficial insects like ladybugs and lacewings, which prey on common tomato pests like aphids and whiteflies. By planting marigolds near your tomatoes, you can create a balanced ecosystem that naturally controls pest populations.


Garlic is a potent companion plant that can help protect your tomatoes from a variety of pests and diseases. A study published in the Journal of Agricultural and Food Chemistry found that garlic contains compounds that can inhibit the growth of fungal pathogens that commonly affect tomatoes.

Garlic also releases a strong odour that can mask the scent of your tomato plants, making it harder for pests to locate them. By planting garlic near your tomatoes, you can create a natural fungicide and insect repellent that keeps your plants healthy and productive.


Borage is a beautiful and beneficial companion plant for tomatoes. Its blue, star-shaped flowers attract pollinators like bees and butterflies, which can help increase tomato yield. Borage is also known to improve tomato flavour and deter tomato hornworms.

Borage contains compounds like gamma-linolenic acid and pyrrolizidine alkaloids, which have been shown to have insect-repelling properties. By planting borage near your tomatoes, you can attract beneficial insects while deterring harmful pests.


Nasturtiums are colourful and edible companion plants that can help protect your tomatoes from pests. These flowers act as a trap crop, attracting pests like aphids and whiteflies away from your tomatoes. Nasturtiums also have a unique ability to secrete a substance from their roots that can repel certain pests and diseases.

Nasturtiums contain compounds like glucosinolates and myrosinase, which have been shown to have insect-repelling and antimicrobial properties. By planting nasturtiums near your tomatoes, you can create a natural pest control system that keeps your plants healthy and productive.

What Not to Plant with Tomatoes

While there are many beneficial companion plants for tomatoes, some should be avoided. These plants can either compete with tomatoes for nutrients or attract pests and diseases that can harm them.


Corn is a heavy feeder that can compete with your tomatoes for nutrients and water. Additionally, corn is often targeted by pests like tomato fruitworms, which can also damage your tomato plants.


Potatoes and tomatoes are both nightshade family members and susceptible to similar pests and diseases. Planting them together can increase the risk of disease transmission and make it harder to control pest populations.


Fennel is known to inhibit the growth of many plants, including tomatoes. It releases compounds into the soil that can stunt the growth of nearby plants, so it's best to keep fennel far away from your tomato patch.


Companion planting is a powerful tool for any tomato gardener looking to maximize their harvest and create a thriving, sustainable garden. By carefully selecting the right companion plants and avoiding problematic ones, you can create a diverse and resilient ecosystem that benefits your tomatoes and the environment.

So, next time you plan your tomato patch, think beyond just the tomatoes and consider the power of companion planting. Your garden (and your taste buds) will thank you!

Frequently Asked Questions:

How close should I plant my companion plants to my tomatoes?

The ideal spacing for companion plants will depend on the specific plants you choose. As a general rule, aim to plant your companion plants about 12-18 inches away from your tomato plants.

Can companion planting completely eliminate the need for pesticides?

While companion planting can certainly help reduce pest populations, it may not completely eliminate the need for pesticides. However, by creating a healthy and diverse garden ecosystem, you can minimize your reliance on chemical pest control methods.

What if I don't have space for all these companion plants?

If you're short on space, focus on incorporating a few key companion plants like basil, marigolds, and garlic. Even a small number of strategically placed companion plants can make a big difference in the health and productivity of your tomato plants.

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