The Best Tomato Companion Plants

Like garlic, onions are also known as natural pest repellents due to their strong odor. They are great companion plants for tomatoes. But, if you’re struggling with thrips in your garden, avoid planting onions, leeks, or garlic near your tomatoes. While they are normally great companions, these root veggies are susceptible to thrips too.

9 Companion Plants You Should Never Grow With Tomatoes (And 5 You Should)

Which species are tomatoes’ friends, and which are their foes?

Tomatoes are one of the most rewarding plants to have in the garden. They are relatively easy to grow, which makes them great for beginning gardeners while still offering a challenge to established green thumbs. If all goes well, they produce gorgeous fruit to eat in sandwiches or throw on pasta. However, before you start cooking and eating your harvest, you must get your plants to grow. One of the best ways to make sure your tomato plants thrive is to surround them with companion plants that can offer soil enrichment and diversification of root systems, as well as management of pests and diseases. Companion planting also helps to keep incompatible plants (those that would rob them of nutrients, block their sun, attract disease, or otherwise harm them) away from each other. Here are plants to avoid growing near tomatoes, and some that you might think about adding to your garden.

Companion Plants To Avoid Growing Near Tomatoes

1. Cabbage

Planting a member of the brassica family, like cabbage, can stunt the growth of your tomato plant because they out-compete them for the same nutrients. Cabbage and tomato seeds both need a lot of nutrients to thrive, so the competition makes one plant suffer—and that’s usually the tomato. In this case, tomatoes may not produce buds, resulting in no fruit and a wasted harvest.

2. Corn

Corn and tomatoes may be great when combined in the kitchen, but not when planted together. This is because they both attract the same sort of pests and fungal infections. Moth larvae feed on both corn and tomato crops, which can destroy any possibility for growth. Putting the vegetables near each other in a garden makes them doubly attractive to bugs, and that will cause double the problems for a gardener hoping for a big harvest.

3. Broccoli

Broccoli, another vegetable in the brassica family, isn’t a good choice for planting alongside tomatoes. That’s because tomatoes are notoriously hungry for nutrients, and broccoli will compete for the same selection of nutrients in the soil. Both plants are heavy feeders, so planting them separately is your best bet if you want them to thrive.

4. Fennel

Like brassicas, fennel will inhibit the growth of tomatoes. Fennel isn’t a good companion for most garden vegetables and should be grown in a little patch or pot by itself. “Don’t plant near bush beans, kohlrabi, or tomatoes because it inhibits their growth,” according to the Colorado State University Extension Service. This licorice-scented plant may work well with other vegetables in your recipes, but not in the garden.

5. Dill

While many herbs grow well with tomatoes, dill is an exception. Young dill plants can actually do quite well next to tomatoes because they are known to help repel aphids, a tiny pest that affects many plants in the garden. However, when dill matures and is ready to seed, the herbs can inhibit tomato plant growth. The mature plants can easily damage the roots of the tomatoes and stunt their future development.

6. Potatoes

Tomatoes and potatoes are both members of the nightshade family, meaning they need the same nutrients to grow. According to the University of Arkansas Division of Agriculture Research and Extension Service, “Potatoes resemble tomatoes more than the other family members and often share the same disease and insects.” If planted together, they will compete with each other, which doesn’t benefit either species and can actually make them susceptible to the same diseases. These diseases can spread through the soil and ruin both plants if one is affected. Also, the proximity of these two plants matters as tomato roots can be damaged when harvesting.

7. Eggplant

Like potatoes, eggplant is in the nightshade family, which making them a competitor to tomatoes. Eggplant is also susceptible to blight, a fungal disease that can rapidly spread through a harvested area via spores blown by the wind. Planting them together makes any tomatoes planted nearby more vulnerable to blight. When sudden browning, yellowing, spotting, or dying leaves appears on crops, this is a potential sign of blight.

8. Walnuts

Choosing to plant tomatoes near a walnut tree may also negatively affect your crop. Walnut trees release chemicals in the soil that stunt the growth of surrounding plants. According to the NC State Cooperative Extension Service, “Tomatoes might grow successfully in the vicinity of a black walnut tree for a while but as the tree grows, so do its roots and eventually the roots will reach the garden.” Once walnut wilt strikes, it won’t take long for the disease to affect the tomato’s fruits, and then the entire plant.

9. Cauliflower

This is another brassica to avoid when seeking out companion plants for your tomatoes. Cauliflower and tomatoes both feed heavily on the soil’s nutrients. If they’re planted close together in the garden, their competition for nutrients will likely result in smaller, less healthy plants. Keep them separate to ensure more opportunities for plant growth and produce development.

Plants That Thrive As Tomato Growing Companions

1. Asparagus

Asparagus and tomatoes are the dynamic duos of the garden. With the help of the chemical solanine, tomatoes deter obnoxious asparagus beetles, which, can do harm to asparagus plants. According to the University of Minnesota Extension Service, “The common asparagus beetle and the spotted asparagus beetle feed on asparagus spears and cause browning and scarring.” A symbiotic relationship exists between the two plants, because asparagus plants, in turn, repel nematodes in the soil. An infestation of nematodes can harm the plants by attacking tomato roots and inhibiting their growth.

2. Chives

Not only are chive plants delicious herbs to have in the garden, but they can repel aphids, nematodes, and mites, making them excellent companion plants for tomatoes. They are members of the allium family and can help keep your tomatoes safe from pests by emitting a strong onion-like fragrance. According to the University of Minnesota Extension Service, “Chives thrive in full sun and well drained soil rich in organic matter. Their grass-like hollow leaves have a mild onion flavor and are common in salads and dips.”

3. Lettuce

If you’re planning a garden that will provide you with salad stuffs, you’re in luck, because lettuce and tomatoes are happy companions in the garden. When you plant lettuce near tomato plants, you will create a ground cover that will help keep the soil moist and cut down on weeds (and weeding). In return, the shade cast by rising tomato plants can help provide some protective cover for the lettuce and stop it from bolting (flowering, which turns the leaves bitter and dry) during the heat of summer.

4. Marigolds

The bright blooms of marigolds attract insects like bees and ladybugs, which are good for a garden, but they also keep away pests like aphids, slugs, tomato worms, and snails, all of which love to munch on your growing tomato plants. These helpful plants also help keep the soil healthy for tomatoes. According to the University of Minnesota Extension Service, “A few studies show that basil and marigolds can be effective at reducing thrip populations in tomatoes in both field and greenhouse conditions.”

5. Basil

Basil and tomatoes are friends in the kitchen, and they can be chums in the garden too. “Basil is a great indicator plant for tomatoes,” as described by the TexasA&M AgriLife Extension Service, “Basil will show powdery mildew and other diseases before it shows on a tomato plant. It may be too late to spray if you wait until the disease shows up on the tomatoes.” According to the University of Minnesota Extension Service, “Intercropping with basil may even help to promote tomato growth.”

The Best Tomato Companion Plants

Tomatoes grow in a bed with peppers, strawberries and basil, as well as flowers that attract pollinators. Photo by: Proven Winners.

Tomatoes are a staple in vegetable gardens and home cooking. Many gardeners plant them in their backyards and in containers because they are rich in nutrients, delicious and productive.

Tomato plants are easy to grow and maintain, but are sometimes impacted by pests, disease, low production or other issues. Luckily, there are vegetables, herbs and flowers that make great tomato companion plants. Below you’ll find a list of 10 plants that you can grow near your tomatoes to help them thrive.

What Are the Benefits of Tomato Companion Plants?

Companion planting is the practice of growing certain plants together to create a mutually beneficial relationship. Make sure the companions you choose flourish in the same conditions so they’ll do well alongside your tomatoes.

Some benefits of growing tomatoes with companion plants:

• They attract beneficial insects that pollinate your tomatoes
• They repel pests that may eat your tomato plants
• They prevent diseases by acting as natural fungicides
• They create an eco-system that is good for everything growing in your garden
• They enhance the flavor of your tomatoes
• They improve yield and increase the quality of your fruit
• They partner well with tomatoes in recipes

Top 10 Companion Plants for Tomatoes

You may want to include some of these common companion plants in your garden:

Photo by: Bruno Glätsch / Pixabay.com.

1. Marigolds

The bright colors and strong scent of marigolds make them an excellent deterrent against insects like tomato hornworms and aphids. These very same attributes can also attract other pests. Planting a row of marigolds around your tomatoes can help ensure that the bugs feed on the marigolds and not on your fruit.

Photo by: Denis Pogostin / Shutterstock.

2. Garlic

Garlic is a natural pest repellent that can help keep moths away from your tomatoes by masking the smell of ripening fruit. It also keeps other pests like cabbage loopers and root maggots away from plants with its strong odor.

Photo by: MabelAmber / Pixabay.com.

3. Onions

Like garlic, onions are also known as natural pest repellents due to their strong odor. They are great companion plants for tomatoes. But, if you’re struggling with thrips in your garden, avoid planting onions, leeks, or garlic near your tomatoes. While they are normally great companions, these root veggies are susceptible to thrips too.

Photo by: Proven Winners.

4. Lavender

The sweet-smelling flowers of lavender plants repel mosquitoes and other flying pests while also keeping aphids away from nearby crops such as strawberries or cucumbers (but not blueberries). Lavender also attracts bees that help pollinate your crops, which can lead to better yields and higher quality produce.

Photo by: Proven Winners.

5. Basil (Ocimum basilicum)

This herb helps control aphids, spider mites, and thrips. It’s also good for repelling mosquitoes because it contains eugenol oil in its leaves, which gives basil its distinctive smell. Many gardeners say that basil also makes your tomatoes more flavorful. Plus, they taste great together in recipes.

Photo by: ganatelier / Pixabay.com.

6. Chives (Allium schoenoprasum)

Like basil, chives will protect against predators like aphids and spider mites by producing natural oils in its leaves that give off an onion-like odor when crushed or brushed up against—a smell most bugs don’t like.

Photo by Africa Studio / Shutterstock.

7. Asparagus

This is a textbook example of a symbiotic relationship between plants. Tomatoes produce a natural chemical called solanine, which is a repellant for the asparagus beetle. In turn, asparagus produces a natural fungicide that helps prevent early blight and botrytis. It also helps prevent root-knot nematodes in the soil.

Photo by 1195798 / Pixabay.com.

8. Celery

Celery is a great bug-deterring companion for tomatoes. Something about the smell puts off many of the bugs that love to eat tomatoes!

Photo by deluna / Pixabay.com.

9. Parsley

If you’re struggling with aphids destroying your tomato plants, you definitely need to plant a barrier of parsley. Parsley attracts hoverflies, and their favorite food is aphids! Be aware though, that not every tomato variety sits well with parsley, so do a little extra research before adding parsley near your tomato plants.

Photo by: Proven Winners.

10. Peppers

This is up for debate, but the general consensus is that peppers and tomatoes are okay together—and you’ll be able to make a mean salsa. But, there can be an increased risk of disease as they are both from the nightshade family.

What Not to Plant with Your Tomatoes

Now that you know the best 10 plants to grow with tomatoes, here’s a list of plants that don’t mix well with them. These plants can actually inhibit the growth of tomatoes by increasing the possibility of diseases and competing for nutrients in the soil.

• Dill
• Eggplant
• Brussel Sprouts
• Cabbage
• Corn
• Cucumber
• Potatoes
• Strawberries
• Cauliflower
• Broccoli

You can find out more about why these plants don’t partner up nicely with tomatoes in this great companion planting guide.

In this video, Lindy @smalltowngardenlife tells us more about our favorite tomato companion plants.

A Note on Beneficial Insects

Frequently Asked Questions

What can I plant with tomatoes in a pot?

Beans, amaranth, basil, and asparagus are a few options. If you have a deep enough pot, you can even try planting carrots.

Can you plant squash next to tomatoes?

Yes, they make great companion plants. Squash have large, broad leaves which help to keep the moisture in the ground.

What family does the tomato belong to?

Tomatoes are part of the nightshade family. Potatoes, eggplants, and tobacco are also part of the nightshade family.

Can you plant zucchini and tomatoes together?

Yes you can! Members of the squash family and tomato plants prefer not to get their leaves wet. That makes irrigating these two crops together much easier.

What flowers to plant with tomatoes?

Nasturtiums, marigolds, and borage are a few. Sunflowers are also an excellent companion for tomatoes.

There are any number of ways to combine a few of your favorite companion plants with your tomato crop. Most of the buddy plants suggested here are edible, so you will be rewarded with an abundance of home-grown and healthy produce.