Companion Plants To Avoid When Growing Tomatoes – Garden Tips 2024

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Companion gardening is when you grow plants together that are beneficial to each other. However, there are some plants that should not be paired together. This article will examine what should and shouldn’t be planted together with tomatoes.

What companion plants to avoid when growing tomatoes: Tomatoes are a member of the nightshade family, so you don’t want to grow other plants in this family, such as eggplant and potatoes. Blight can spread too easily among this family of plants. Also avoid any plants from the brassica family, such as cabbage, broccoli, and cauliflower. These are all heavy feeders and will take all the nutrients from the soil, which will result in your tomatoes being smaller in size.

What is companion planting?

Instead of merely planting your favorite crops in your garden, if you can plan the area ahead of time, you will have larger, healthier plants. This is because some plants do well next to each other while others don’t.

Some plants will ward off certain insects and are beneficial in this regard while others attract useful insects or pollinators.

In contrast, some plants will attract the same sort of diseases which can lead to entire crops being wiped out. Furthermore, some plants will compete for an excess of nutrients, which results in stunted growth and poor yield.

10 Companion Plants to Avoid When Growing Tomatoes


We might sound too dire, but cabbage is probably the worst plant to pair with growing tomatoes. This is because cabbage will actually stop the growth of tomatoes.

Cabbage is considered a heavy feeder, which means it will absorb all the nutrients in the soil. Tomatoes also require a lot of nutrients, so there won’t be enough to sustain both plants.


Both cauliflower and broccoli should be avoided when planting your tomatoes. Like cabbage, they belong to the brassica family and will take in all the available nutrients in your garden.

If you do decide to plant cauliflower or broccoli, be sure to space them out so they aren’t competing with each other for nutrients. Furthermore, start with rich soil and add a slow-release fertilizer every month to sustain the plants.


An issue with corn, no matter what it is planted near, is the highly destructive corn earworm moth. This pest will consume all parts of a corn plant but will also travel to other nearby plants.

The larvae of the moth love tomatoes and will easily tunnel their way through the soft flesh, as well as the leaves and stems. Unfortunately, once this pest starts growing, it is hard to eradicate them.


Both eggplants and tomatoes are susceptible to blight, so it’s best to err on the side of caution and not plant the two near each other. This way, if one crop has blight, it won’t spread as easily to the other.

With early blight, the foliage of the tomatoes is affected and will cause the leaves to turn brown and fall off, resulting in slower growth. Then, with late blight, the fruit is affected, leaving the tomatoes inedible.


Fennel is an overpowering crop and unfortunately, does not pair with most plants, especially tomatoes. The problem is that fennel roots can release a chemical that will prevent the growth of tomato plants.

It’s best to plant fennel in its own pot so that the roots are contained and can’t cause any destruction to nearby plants, especially tomatoes.


While you can grow dill next to tomatoes when the dill plant is still young, once it matures the relationship takes a turn for the worse. Young dill will actually repel pests, such as aphids.

However, mature dill will take in too many nutrients and prevent the growth of tomatoes. If you have the two plants near each other, dig up the dill before it goes to seed.


Even though you might not think it, tomatoes and potatoes both belong to the nightshade family, which means the same diseases that affect potatoes will affect tomatoes. The result is that both crops can become affected at the same time.

Another issue that can arise is if the roots of potatoes grow too close to tomatoes. Then, the growth of tomatoes can be affected and result in smaller sizes of tomatoes.


When walnut trees grow, they release a chemical that can stunt the growth of nearby plants. This toxin is called juglone and when it reacts with oxygen, it becomes toxic.

Walnut trees should be grown away from other plants but tomatoes seem to be especially sensitive to it. Furthermore, never throw walnut shells into your compost as this toxin can spread to the rest of your garden.

Brussels sprouts

As a member of the brassica family, brussels sprouts behave the same way that cabbage does to tomatoes They take all the nutrients in your soil and won’t leave enough for your tomatoes.

It is much better to plant brussels sprouts far away from tomatoes and indeed, to leave a larger border between other plants so there is less competition for nutrients.

Hot peppers

While healthy hot peppers are fine to grow next to tomatoes, the issue arises if they develop diseases, particularly blight. Hot peppers also belong to the nightshade family, just like eggplant and potatoes, so the blight can easily move to the tomatoes.

If you do plant hot peppers for one year, it is best to plant them in a container. Blight can live in the soil for up to three years, so if there is an infection, it can wreak havoc on other plants for years to come.

10 Plants that Go well with Tomatoes


If you take a look at established gardens, you will often see the bright orange flowers of marigolds around the border. These plants are incredibly beneficial to tomatoes and your garden as a whole.

Marigolds attract ladybugs and bees which not only help to pollinate a garden but also repel aphids and slugs. They also create a healthy soil environment for your tomatoes.


Both tomatoes and asparagus have the ability to repel insects and because they target different insects, they make for excellent companion plants. Tomatoes will keep asparagus beetles at bay while asparagus will repel nematodes.


The strong scent of chives is an excellent natural deterrent to many insects. Chives will repel nematodes, mites, and aphids, which is perfect as these pests like to flock to tomatoes.


An example of an amazing symbiotic relationship can be found between lettuce and tomatoes. The two plants and their different heights make for great companion planting.

The low growth of lettuce keeps the soil moist which aids in water retention for tomatoes. Then, the height of the tomatoes provides natural shade for lettuce.


When cooking, tomatoes and basil are natural companions. The same is true in the garden.

The sweet fragrance of basil helps to repel insects such as fruit flies and mosquitos. Basil also creates better soil conditions and the flavor of the herb can actually transfer to tomatoes as they grow, creating more robustly flavored fruit.

Bush beans

Even though bush beans don’t work to ward against insects, the very nature of their growth pattern will improve the growth of tomatoes. This is because their size will increase air circulation which results in improved growth and less dampness on the tomato plants.

It’s important to note that only bush beans provide this benefit. Pole beans are too tall and narrow.


Some people may think clover plants are a weed but this plant has a lot of benefits. Sweet flowers attract important pollinators such as bees, so clover should be promoted whenever it grows.

Furthermore, clover releases nitrogen back into the soil, which provides important nutrients for tomatoes, which are heavy feeders.

Black-eyed peas

Interestingly, black-eyed peas, also called cowpeas, attract insects instead of repelling them. However, they act as a sacrificial plant in your garden.

One pest, in particular, the southern green stink bug, loves black-eyed peas and will flock to this plant, leaving your valuable crops, such as tomatoes alone.


Another plant that can be used in a sacrificial manner is radishes. These will attract flea beetles so they feed off the radishes and not your tomatoes.

For optimal results, plant radishes close to tomatoes, right at the base of the plants. Radishes grow quickly and don’t take up a lot of room in the soil.

Sweet alyssum

There are many flowers that go well in a vegetable garden, sweet alyssum included. The white flowers will attract parasitic wasps, which, despite the name, are actually classified as good bugs.

These wasps will then eat problematic pests such as aphids. Not all pests are bad and attracting the good kind will stop bad pests from taking over your plants.


When planting tomatoes, stay away from plants in either the nightshade family or the brassica family. Instead, plant beneficial companions such as marigolds, basil, and lettuce.

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