Tomatoes are a staple in many gardens, and companion planting is a natural way to enhance your tomato plants' health and yield without resorting to chemicals.
Certain plants, when grown alongside tomatoes, can deter pests, attract beneficial insects, and even improve soil health. Let's dive into the world of companion planting and discover the best allies for your tomato plants.
Top 10 Companion Plants for Tomatoes
In the quest for a bountiful vegetable garden, incorporating the right companion plants for tomatoes can significantly boost plant health and crop yield. From deterring pesky insects to improving soil health, these top 10 companions are a must-have in any tomato lover's garden.
Companion planting can be one factor that sets great gardeners apart from good gardeners.
Growing the right plants next to your tomatoes can be incredibly beneficial, so why not try it with these handy companion plants.
1. Basil

Basil and tomatoes both thrive in warm conditions. For this reason, they will grow very happily alongside each other.
Because they like the same conditions, you can also use the basil as a barometer for how well-suited the conditions are.
You will be able to see earlier with the basil whether it is happy or not, and if the basil is happy, then your tomatoes will be happy.
Also, basil will grow underneath cordon-trained tomatoes. This won't work the same way with bush tomatoes, which must be grown side by side.
Some people also swear it helps to drive away harmful pests that may otherwise damage your tomatoes, but some gardeners have also reported it making no difference.
2. Marigolds

Marigolds are a great companion plant for many different vegs, but they are particularly great when grown with tomatoes.
Scientists have been able to demonstrate that marigolds help protect tomatoes against nematodes.
While the science may not be as solid on the following, ask a lot of gardeners, and they will swear those marigolds also deter whitefly and aphids.
The bonus is that the bright yellow flowers of marigolds will help attract pollinators to your tomato plants.
3. Coriander

Coriander is commonly grown in the greenhouse as a companion plant for tomatoes. Gardeners grow coriander with tomatoes as it is reported to help deter whitefly and aphids.
These are two pests that can really take a toll on your tomato plants so planting a little coriander could go a long way.
Again there are no strong studies to back this up but a whole heap of people will swear by it, then others will tell you it doesn't work!
4. Lettuce

Lettuce makes a great companion plant for tomatoes, especially cordon-grown tomatoes.
Lettuce doesn't work well with tomatoes because of any pest prevention like the plants above, but rather because lettuce can be grown under tomato plants, maximising your space usage.
Lettuce grows close to the ground and cordon-grown tomatoes will grow nice and high. What this means is that there will be plenty of room under the tomatoes, which would otherwise go to waste.
So why not pop a few lettuce plants in there and make the most of your prime growing space?
This is particularly useful for tomatoes grown in a greenhouse, ensuring you get the most out of your prime real estate.
5. Onions
Onions are an excellent companion for tomatoes, providing a barrier against various pests. Their pungent smell is effective in deterring many pests, and they can help protect tomatoes from underground pests too.
6. Chives
Chives, with their subtle onion-like taste, are not only a great culinary addition but also deter aphids and spider mites from tomatoes. The natural oils released from chives provide a protective barrier against these pests, enhancing the overall health of tomatoes.

7. Parsley
Parsley can attract beneficial insects like hoverflies, which prey on common pests like aphids. This herb acts as a companion by fostering a balanced ecosystem around tomato plants, leading to healthier growth and better yields.
8. Calendula
Known for their bright flowers, calendulas attract pollinators while also deterring certain pests. Their role in promoting beneficial insects aids in the natural defense of tomatoes.

9. Nasturtiums
Nasturtiums serve as a trap crop for aphids, drawing them away from tomatoes. Their vibrant flowers not only add beauty to the garden but also encourage a healthy ecosystem by attracting pollinating insects.
10. Oregano
Oregano is another herb that's beneficial for tomatoes, deterring various pests and diseases through its strong aroma.
11. Sweet Alyssum
Sweet alyssum, with its delicate white flowers, attracts beneficial predatory insects, such as hoverflies, which feast on aphids and other tomato pests. This low-growing plant can be easily integrated into the spaces between tomatoes, providing a living mulch that enhances biodiversity.
What Are the Benefits of Tomato Companion Plants?
Pest Control stands out as one of the primary reasons for integrating companion plants into tomato gardens. Certain plants repel harmful insects naturally, reducing the need for chemical pesticides. For instance, marigolds are famous for deterring nematodes in the soil that could otherwise harm tomato roots. Meanwhile, basil emits a strong scent that not only repels pests but can also enhance the flavour of tomatoes nearby.
Attracting Beneficial Insects is another critical advantage. While some insects are detrimental, others are vital for pollination and controlling pest populations. Companion plants like borage and calendula attract bees and other pollinators, ensuring tomatoes are well-pollinated for a robust yield. Moreover, plants such as sweet alyssum can lure beneficial insects that prey on common pests like aphids.
Soil Health is significantly impacted by the choice of companion plants. Legumes, for example, fix nitrogen in the soil, a nutrient essential for the healthy growth of tomatoes. Pairing tomatoes with beans or peas can naturally enhance soil fertility without artificial fertilisers. Furthermore, some companion plants act as living mulch, conserving soil moisture and suppressing weeds that would otherwise compete with tomatoes for nutrients.
Disease Prevention can be indirectly influenced through companion planting. By promoting a diverse ecosystem, the risk of soil-borne diseases can be minimised. Plants such as garlic and chives are believed to have antifungal properties, offering a layer of protection against common diseases that affect tomatoes.
Increased Biodiversity within a garden has overarching benefits beyond the health of the tomato plants. A diverse planting strategy creates a more resilient ecosystem, able to withstand fluctuations in weather, invasive species, and disease outbreaks. This harmonious balance encourages a natural cycle of growth, decay, and regeneration, which can lead to a healthier garden environment overall.





Gina Freer says
Excellent advice, so if growing tomatoes I'm frow bags would I plant the marigolds in there aswell
Daniel says
I would plant them in pots and place them near the tomatoes. Tomatoes in bags will use up all of the nutrition so your marigolds probably wouldnt do too well