The concept of companion planting is not something new. It is a way of using one plant to help the other by stopping certain diseases and insects from being able to take root in the plant therefore preserving its health. However, you need to know which plants go together to make this work and in this instance we will focus on plants that you should, or should not, put with tomatoes.

The Best Companion Plants for Tomatoes.

1. Basil.

If you have never thought about basil and tomatoes together, then now it is time to change that idea. It has been shown that basil and tomatoes planted together will actually enhance both the flavor and the way in which the plants grow. Furthermore, the basil is going to help to repel thrips and also flies from your tomato plants helping the growth even further.

2. Borage.

Borage is an edible flower and it also goes well with tomato plants and it helps for one problem in particular, tomato hornworm. This is a type of caterpillar that is capable of eating away at the leaves of the plant but it hates borage which is a good enough reason to use it.

3. Chives.

Chives are not only a good herb to use in cooking but by planting them close to your tomato plants you are going to help give some added protection. This is because of the aroma that is given off by chives and this has been shown to be an effective way of repelling various insects, but in particular aphids, that are just not best pleased by the smells that they encounter.

4. Garlic.

Garlic works in the same way as chives as it is the aroma that is also going to work at repelling insects due to the way in which it can really penetrate the atmosphere. Furthermore, the fact that it does not harm the tomato plant itself is just a bonus but you will certainly see a difference in the number of insects that are attracted to the plant. The plant is brilliant at repelling spider mites.

5. Marigolds.

This might sound strange to a number of people, but marigolds are amazing at helping to protect a variety of plants and tomatoes are just one of them. The key part is in the roots because they emit a particular substance into the soil that kills nematodes in the soil and they are also known to keep white fly away from your tomato plants and they are a huge pest to deal with as the white fly cannot stand the smell of the flowers.

6. Mint.

The problem with mint is that it is very invasive so you have to be careful as it will take over the space for the tomato plant. However, it can also help to protect your tomato plant in a number of ways as it is known to be a deterrent to several pests including aphids, flea beetles, fleas and white cabbage moths amongst other things.

7. Nasturtium.

Once again we look to a flower for some companion planting and this time it is nasturtium and one cool thing is that it is not going to take some of the nutrients away from your tomato. They not only protect the plant against white fly, aphids, and beetles but they can also help to prevent a variety of fungal diseases from attacking your tomato.

8. Parsley.

Parsley is a wonderful herb to grow and it can also offer some protection to your tomato plants although you have to deal with the fact that it is not too keen on heat. However, it is a wonderful plant because of the way it works. It does not repel certain pests but rather hoverflies are attracted to it and they love eating a variety of the different pests that then end up on the tomato.

9. Carrots.

Yes, carrots can be a fantastic companion plant for tomatoes and a number of people absolutely swear by it. Carrots help as their roots will break up the soil that is around the roots of the tomato plant and will then allow for more nutrients to be absorbed as well as additional air. You will then have a healthier crop of tomatoes.

10. Peppers.

Peppers are another amazing plant to grow alongside tomatoes. They are part of the same family as tomatoes so they are not going to fight against one another. In actual fact, they share a number of the same characteristics so you can effectively grow both alongside one another quite happily.

11. Celery.

Celery helps in balancing out the soil with tomatoes and it can also help to repel certain aphids and flies that can cause problems with the tomato plant or the fruit itself.

12. Onions.

Onions will also work in the same way as chives and garlic as it is the pungent aroma that they emit that keeps so many different pests away. Also, they are not going to negatively influence the tomatoes either so there is no need to be concerned about that but the smell is enough to provide some extra protection.

13. Petunia.

The idea of planting petunias beside tomatoes is perhaps not the first thing that you would think about but as with other flowers, this has been shown to be quite an effective tool. The main way in which they will benefit your tomatoes is by repelling tomato worms so it is certainly something that you should give some serious consideration to.

14. Asparagus.

Asparagus is seen as being a complimentary plant to put alongside tomatoes and it is often because of one major reason and that reason is the way in which they can repel root nematodes. This is going to prevent issues developing with the roots of your tomato plants leading to a better harvest.

15. Calendula.

If you are serious about growing tomatoes that are not covered in insects and pests, then planting some calendula around the plant is certainly something to consider. The calendula is, of course, closer to the marigold and it has been shown time and time again to be a wonderful way of repelling a whole host of pests and insects that do not like either the aroma or the nutrients that it puts into the soil.

16. Dill.

Even though dill may not be the first thing that you think of when it comes to companion planting with tomatoes, it does actually help. However, you need to be careful in what you do as this is a herb that can easily switch from being helpful to hindering your ability to grow nice and healthy tomato plants. Make sure that your dill is young plants and then harvest the plant before it matures. Young dill has the ability to enhance tomato plants and make them healthier but then mature plants can do the opposite which is why you have to remove them.

Worst Companions for Tomatoes.

Now, we have just looked at 16 different plants that can work well alongside tomatoes and often be of mutual benefit to one another, but that is not always the case with every single plant. Instead, there are some plants that are like an enemy to the tomato and you should never have them anywhere near one another. They can either attract pests, diseases, or even compete for nutrients but at the end of the day you will have a poorer tomato plant as a result.

So, the companions that you need to steer clear from include the following:

17. Black Walnut.

You should never have black walnut anywhere near a tomato plant and it is for a very good reason. The black walnut will produce something called juglone and this can be toxic to tomatoes and, as a result, inhibit their growth. In addition, it can also lead to something called walnut wilt and any kind of wilt on a tomato plant is always going to be bad news.

18. Brassicas.

By brassicas we mean things such as cauliflower, broccoli, kale, and sprouts and you should never plant them together under any circumstances. The problem is that they are going to repel one another and, in the process of doing so, they are going to inhibit growth of one another so you would end up with poor cauliflower and also poor tomatoes.

19. Corn.

Corn is another plant that you must avoid putting alongside tomatoes as they just do not get along with one another. In short, they are real enemies and it is all because of one very good reason, they are able to attract pests that are dangerous to the other. Corn is going to attract the tomato worm while tomato plants ironically attract the corn worm so you end up with both plants being destroyed and no produce at the end of it.

20. Fennel.

Fennel is of course a herb, but unlike others that help the tomato plant this one is going to work against it. You will tend to find that fennel planted close to a tomato plant will only inhibit the growth so forget about this herb and focus on basil or parsley instead as they are certainly far more beneficial to the tomato plant.

21. Potato.

The humble potato is also capable of being a real enemy to your tomato plants and even though it is not going to attract any kind of unwanted pests as such, it is still something to be avoided. Instead, if you plant the two together then you are going to open up the possibility of your tomato plants suffering from late blight which is going to be a real disaster for your crop.

22. Sprouts.

Sprouts might be popular, but they are certainly not popular for your tomato plant. They are also part of the brassica family and as we pointed out earlier on they are going to really inhibit the growth of your tomatoes. Remember, inhibited growth is going to then lead to fewer tomatoes for all of the effort that you have put into growing them.

23. Cabbage.

Cabbage is going to be a huge mistake if you decide to plant it next to your tomatoes as you are only going to be asking for trouble to come your way. They are also capable of restricting growth when it comes to your tomatoes just in the exact same way as sprouts. Also, there is a tendency for them to attract various pests including whitefly so they are also going to attack your tomato plants at the same time causing chaos and mayhem.

24. Cauliflower.

Cauliflower might be delicious, but your tomato plants would disagree thanks to the way in which this particular vegetable can cause all kinds of problems for your tomato plants. They will also slow down and restrict the potential growth of your tomatoes leading to a smaller yield. They enjoy different conditions and will compete against one another for various nutrients and more often than not it is going to be your tomato plants that will lose out.

So, as you can see there is a rather extensive list of plants that you might want to put next to your tomato plants in order to help them along with a number of them that should never be put anywhere remotely near your tomatoes. Having this kind of an understanding is undoubtedly going to have a major impact on what your harvest is like or even if you are going to be able to have a harvest at all.

Companion planting is something that has been studied and researched extensively and it does actually produce results so do not sit there and think that this is some crazy nonsense. It makes a difference and as long as you provide your tomato plants with a number of other key things that it needs then you can look forward to some pretty impressive results.