What Should Not be Planted with Tomatoes? (Worst Companion Plants)

Harvested Red Tomatoes

Tomatoes are classified as fruit. They do not mix very well with many crops, so a terrible combination could reduce your yield or damage the plant’s health. Several plants should not be planted around tomatoes. In this article, we have compiled a list of plants that should not be planted with tomatoes.

Plants That Cannot Be Planted Alongside Tomatoes

Cabbage (Brassica) Family

Tomato plants’ development is slowed by all cabbage relatives, including Brussels sprouts, broccoli, kale, collards, kohlrabi, cabbage, and rutabaga cauliflower, and turnip). Cabbage and tomato plants are not meant to be together. Growing these crops next to each other could result in stunted growth.

Tomatoes and cabbages have a tendency to fight for root space. On the other hand, Tomatoes have a harder time spreading their roots, resulting in smaller fruits. Tomato plants often grow tall, obstructing any plants that grow too low to the ground, such as cabbages.


The tomato fruit worm is the same as the corn earworm. Growing plants that are vulnerable to the same insects nearby can lead to disaster and a ruined garden. Corn and tomato plants do not get along because they both have the same insects, the tomato fruit worm and the corn earworm (the cotton bollworm).

Such crops may draw nibbling pests if grown side by side, and the damage would be even more serious because worms love corn and tomatoes. And if these licking insects become too at ease, they will decimate the entire garden!


Mature dill plants inhibit the growth of tomato plants. Plant the dill that you would like and ensure it grows away from the tomatoes.

Eggplant, Peppers, and Potatoes

These plants, like tomatoes, are nightshade plants. They are all vulnerable to early and late blight, which can build up in the soil and worsen year after year. For at least three years, avoid planting them close to or in place of one another.

Hornworms (Manduca quinquemaculata, the larval stage of the 5-spotted hawkmoth) are attracted to the foliage and fruit of tomatoes, peppers, and eggplants. They can easily devastate plants. Tomatoes planted near potatoes can also make them more vulnerable to potato blight.

Blight is caused by certain diseases that lead to the death of plant cells. Browning, shading, and shuddering of plant leaves effect as a result of this. If grown together, eggplant and tomato plants can contract the same disease. It could cause blight to develop in the soil and worsen year after year. Worse, if these plants are grown together, blight will spread throughout the garden.


Much like walnut trees, fennel also contains a toxin that stimulates root and plant development. That will eventually be causing stunted growth and fewer fruits in tomato plants. Fennel is not a suitable partner for a lot of plants because the chemical it creates affects so many garden plants.

It is strongly advised to designate a separate section of the garden for fennels. Retain the fennels much further away as possible from other garden plants and crops. Also, remember that Dill is the only plant that can withstand the effects of the chemical generated by the Fennel.


Tomatoes should not be planted near walnut or butternut trees. It is simply because these trees produce an allelopathic chemical called juglone, which inhibits tomato development (and similarly affects all the members of the nightshade family). The illness of walnut wilt affects tomatoes as well.

Plants That Can Be Planted Alongside Tomatoes


Borage is an excellent tomato companion plant because of its ability to repel various tomato pests, especially hornworms. When used as an herb, this flowering plant will help tomato fruits grow faster and taste better.

Many farmers suggest that growing tomatoes alongside borage makes them taste better. Borage, on the other hand, gives salads and summer drinks a refreshing cucumber taste!


Marigolds, with their bright golden yellow blossoms, are always a welcome addition to the garden. And, when planted alongside tomatoes, you should expect a bumper crop! Marigolds have been shown to protect tomatoes from root-knot nematodes, tomato hornworms, whiteflies, and bacterial blight, according to research.

Marigolds are also said to shield tomato plants from rabbits and other large animals, according to some growers. Since tomato plants and marigolds grow in similar environments, it’s simple to include the latter in a vegetable garden.


Carrots and tomatoes go really well together because they enhance one another in so many ways. Once cultivated beside each other, carrots can enhance the flavor of the tomatoes. Some farmers are wary of growing these crops together as their roots can interfere with each other.

However, if you want sweet, flavorful, delectable tomatoes, there is no greater compatible plant than carrots. Give carrots and tomatoes a little more room between them if you are growing them together. The tomato fruits will be larger and not stunted as a result of this process.

Bell Peppers

Since their flavors enhance each other, bell peppers and tomatoes make good companions. Bell peppers and tomatoes also deter rodents from nibbling on them. On the other hand, Tomatoes grow tall and will cast a shadow on the shorter bell pepper plants. When growing these two crops together, make sure they get plenty of sunlight.

Leaf Lettuce

Tomatoes and leaf lettuce flourish well with each other since both plants prevent the spread of rot-causing diseases. Lettuce suppresses the growth of weeds, which could reduce the nutrients available to both crops. Tomatoes, on the other hand, keep pests at bay while taking up minimal space.

Your Plants’ Health Depends on your Garden Layout

The layout of your garden, especially your vegetable garden, will impact your plants’ health. That is why it is critical to understand which plants work well together. Vegetables should not be grown in large groups because this encourages the spread of pests and diseases.

Companion planting is a vital factor when planning a vegetable garden. It entails growing different crops close to each other to increase growth, pest control, pollination, and nutrient absorption.

Some plants get along swimmingly, and others do not get along at all. You can establish the best growing environment for tomatoes by choosing the right companion plants for them.

Plants Can Complement Or Repel Each Other

Some plants complement each other, and other plants should be separated. It can be challenging to integrate the two groups into a garden plan, particularly in a small room.

Tomatoes are one of the most common home-garden plants. Though they can produce less-than-ideal results, if you want to increase your yields, consider companion planting next to your tomatoes. Fortunately, there are a plethora of tomato plant companions.

Tomatoes Are Easy to Grow

The advantage of cultivating tomatoes is that the plant will produce many fruits in a short period. Unlike many other crops, the tomato plant is so easy to cultivate. It only needs full sun and daily watering. However, if you want to increase your tomato production, it is highly recommended that you try companion planting.

Just Get the Right Companions to Plant with them

Tomatoes go well with a variety of common garden vegetables. Few companion plants are said to aid in the health and vigor of tomato plants, while others are said to enhance tomato flavor and repel and deter insect pests and diseases.

So, just like people who get on with, or avoid each other, tomatoes are similar.

The takeaway here should be that whatever you need to do to grow a crop of exceptionally healthy tomatoes by knowing which plants help and which do damage, is all contained within this article. Grow those tomatoes and enjoy them. They bring us amazing health benefits. Enjoy!

Jenny Marie
Tribal Writer

Edited By
Patricia Godwin

Patricia Godwin

Patricia has many years of experience as a content writer on various subjects, but her first love is gardening. She’s never met a plant she didn’t like and, consequently, she writes about every type of plant you can think of. Once an avid gardener with a herb garden, a succulent rockery, and a rose garden – to mention a few. Nowadays, she’s constantly on the move searching for interesting plants to bring to your attention; and explain to you all the details you need to grow, care and maintain these plants.

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