What NOT To Plant With Tomatoes

Planning your garden and considering companion plants is one of the best things you can do in the weeks leading up to planting season and when making additions to your garden throughout the season.

Most gardeners choose to grow tomatoes and find themselves looking for what is good to grow along with them to make the most of their garden space.

While there are a lot of amazing plants to grow with your tomato plants there are some that you should avoid, helping ensure that your tomato crop can thrive.

Unripe plum roma tomatoes growing with marigold and calendula

Why You Need to be Careful of What You Grow With Tomatoes

Tomatoes are very heavy feeders that need a lot of water to thrive. When you are planting your tomatoes you want to be sure that you are not planting anything with them that will take what your tomatoes need or produce substances that will stunt the growth of your tomato plants.

You want to avoid shading your tomato plants that need full sun to produce a thriving crop. Another issue you may find is that your tomato plants grow rather large, which can shade nearby plants that need full sun to thrive.

For the best results, plan your tomato garden so that it is only shading plants that benefit such as cold weather crops to help extend their growing season.

Plants to Avoid Planting Near Tomatoes

Not all plants make great companion plants for tomatoes. While some such as basil and green beans make amazing companion plants for your tomatoes. These plants are ones that you should avoid for the best results in your garden.


Fennel is one plant that you should really consider never growing directly in your garden. This herb releases a toxin that kills off most other plants in your garden including your tomatoes. If you wish to grow fennel at home, grow it in a pot so you do not have to worry about the spread of this toxin.

If you stop growing fennel do not use that soil for growing other plants as the toxin will affect them as long as it is inside the soil.

Broccoli and Cauliflower

Broccoli and cauliflower do not tend to share space well in the garden and take up a large amount of space to grow. These plants are best kept in a garden bed of their own or with plants that are good companions for them.

These plants also produce chemicals in the soil that will slow the growth of your tomato plants. Because of the chemicals released by these plants, many things should not be grown with these two plants.


Cabbage takes up a lot of space to grow and the root system is at a similar depth to your tomatoes. This means you can not grow these together or you’ll risk the cabbage stunting the growth of your tomatoes. The tomatoes will also shade your cabbage plants too much, preventing them from growing to their full potential.


Corn has a shallow root system that tends to fight with tomatoes and other shallow root plants for dominance. Corn will also tend to provide too much shade blocking tomatoes from having the room to thrive. While tomatoes need support to grow and corn makes a great support plant, these two do not make a good pairing.


Dill makes a great addition to your garden but is best kept away from tomatoes. The roots of the dill plant will cause issues for tomatoes. Full-grown dill can lead to reduced growth of your tomato plants. If you need to start these near each other that is fine but avoid allowing your dill to reach maturity in the garden near your tomatoes.


Eggplant is a wonderful and versatile plant that works well in many areas of your garden but eggplants are a nightshade, and like tomatoes are a heavy feeder of the same nutrients. Because of this, you want to avoid planting eggplant near your tomatoes and other nightshades as they may compete for the same vital nutrients.


Walnut trees are not something you would usually think about growing near your tomatoes because they provide lots of shade but it can be quite interesting to know that walnuts also release chemicals into the soil that are toxic to tomatoes and will reduce the growth of the plants over time.


Potatoes are a great addition to your garden but they are very heavy feeders and will compete for the space and nutrients your tomatoes need to thrive. Pairing heavy feeders is a bad idea in the garden.

Be sure to not plant potatoes and tomatoes in soil that the other plant was grown in during the previous year.

grow lots of tomatoes

And for more information on companion planting to help you plan your garden, check out these guides next: