If you want to grow healthier tomatoes (Solanum lycopersicum) and get a bigger harvest, you should consider intercropping. This means growing other plants next to your tomatoes that can help them thrive.
These companions will make it easier for you to grow strong, productive tomato plants while also saving space and effort.
1. Common Bean (Phaseolus vulgaris ‘Bronco’)
When tomatoes and common beans were grown together in a field experiment, the results showed that it could be a successful combination without harming the tomato yields. This means that you can grow both crops together without sacrificing tomato production.
The presence of common beans boosted their yields. This happens because the beans can fix nitrogen in the soil, which benefits both crops. (ref)
Not only do you get a good harvest from your tomatoes, but the common beans also perform well, improving overall profits. This type of intercropping can be a win-win for you if you’re looking to maximize the space in your garden and boost your yield without negative effects on tomato growth.
2. Lettuce (Lactuca sativa)
Intercropping tomatoes with lettuce can be beneficial because, according to the study, tomatoes grow well in this combination.
While tomatoes don’t show overall negative effects from being grown alongside lettuce, lettuce does experience some stress due to competition for resources like sunlight, space, and nutrients. However, despite this, there are still economic benefits. (ref)
Lettuce grows quickly, so if you can manage the intercropping system properly, it can bring in additional income without harming the tomato crop. This makes intercropping tomatoes with lettuce a great option for small and medium-sized farms looking to diversify their crops and increase profits.
3. Potato Onion (Allium cepa var. aggregatum)
A potato onion, also known as a multiplier onion, is a type of onion that grows in clusters, like potatoes. Unlike common onions that grow from single bulbs, potato onions produce multiple bulbs that are about the size of a large marble.
The study from Frontiers in Plant Science shows that planting potato onions alongside tomatoes helped tomatoes grow better and take in more phosphorus (a nutrient) when the soil already had a lot of phosphorus. It also changed the types and actions of helpful bacteria in the tomato roots. Also, growing potato onions with tomatoes improved the soil by reducing acidity and salt levels. (ref)
Potato onions are known for their strong flavor and hardiness, which makes them a popular choice for gardeners in cold climates. Plus, they store well, so you can enjoy their pungent flavor all winter long.
4. Spinach (Spinacia oleracea)
The Pharma Innovation Journal found that intercropping tomatoes with spinach in improved tomato growth and quality. (ref) This means that when you plant spinach alongside your tomatoes, it doesn’t harm the tomato plants but may help improve their growth and the quality of the fruits.
Spinach is a relatively low-growing crop, so it likely doesn’t compete for sunlight, allowing the tomatoes to thrive. It’s a good choice if you’re looking for a simple intercropping strategy that doesn’t harm your tomato plants.
5. Carrot (Daucus carota subsp. sativus)
The same study in the Pharma Innovation Journal also suggests that the best results for tomato yield and profit came from intercropping tomatoes with a mix of crops, including carrots. This means that planting tomatoes with these crops together helped maximize the total harvest—the other crops in addition to the tomatoes.
The tall, lanky tomatoes provide a trellis-like support for the shorter, bushy carrots, creating a mini-greenhouse effect that can help protect the carrots from pests and frost. Plus, tomatoes and carrots have different nutrient requirements, so they won’t compete with each other in the soil.
6. Coriander / Cilantro (Coriandrum sativum)
The Pharma Innovation Journal also implies that planting tomatoes with coriander could have positive effects on tomato growth. Coriander is another low-growing herb, so it likely doesn’t compete much with tomatoes for space or sunshine.
It could potentially even help by attracting beneficial insects that might protect your tomato plants from pests. Just be sure to give your plants enough space so they don’t overcrowd each other and hinder growth.
7. Radish (Raphanus sativus)
Radishes can be a great companion plant for tomatoes in your home garden. According to the Annals of Plant and Soil Research journal, researchers found that growing radishes between tomato rows can make efficient use of space and help improve overall garden health. (ref)
Radishes grow quickly and don’t take up much room, so they’re perfect for planting alongside slower-growing crops like tomatoes. While intercropping radishes with tomatoes can result in good growth, keep in mind that the radishes may produce slightly smaller roots compared to when they’re grown on their own.
However, the benefits of intercropping—such as better use of garden space and potential pest management—can still make this a worthwhile strategy for home gardeners who are not focused on large-scale production.
8. Small Onion (Allium parvum)
Small onions can grow well alongside tomatoes when planted between tomato rows. According to the same Annals of Plant and Soil Research journal, small onions grown in this intercropping system showed good growth.
This setup allows both crops to benefit from shared space while optimizing the use of available resources. Also, the tomatoes provide some shade to the onions, protecting them from excessive heat, which can improve onion growth.
This system can even help in reducing the spread of certain pests that affect either crop. The onions, in turn, can help suppress weeds, improving overall soil health.
9. Vegetable Cowpea (Vigna unguiculata)
In the same Annals of Plant and Soil Research study, the research on vegetable cowpeas grown alongside tomatoes showed mixed results. While cowpea grown by itself produced larger pods, more pods per plant, and a higher yield, the intercropping system resulted in smaller pods and fewer pods per plant.
Even so, the intercropped cowpea still performed better than when intercropped with other crops, showing that this particular combination of crops and fertilizers helped maintain decent yields. Although it wasn’t as productive as the sole crop, it still provided better results than other treatments.
10. Basil (Ocimum basilicum)
If there’s one herb that’s a match made in gardening heaven for tomatoes, it’s basil. For one, basil attracts beneficial insects like ladybugs and lacewings, which prey on the pests that love to munch on tomato plants.
And it’s not just about bug control—planting basil near your tomatoes can improve their flavor!
In an Agronomy study, this arrangement (1 tomato:1 basil) results in the highest tomato yield, proving that basil can be a great companion plant for tomatoes when the spacing is planned well. (ref)
11. Wheat (Triticum aestivum L.)
Wheat is a cereal crop that needs a lot of nitrogen in the soil to grow well. Tomatoes, on the other hand, need less nitrogen, but they benefit from the shade that wheat provides.
Planting wheat with tomatoes can also help protect tomatoes from cold and frost during winter. This reduces damage to flowers and fruits, improving tomato growth and productivity.
In a paper published by the Annals of Agricultural Sciences, the Intercropping wheat at half its usual seeding rate with tomatoes, planted on November 15th, increased fruit setting, total yield, and marketable harvest. This system also gave farmers the highest profits. (ref)
12. Rue (Ruta graveolens)
Rue is a strong-smelling herb that can repel a whole host of pests that love to munch on tomatoes, like aphids, flea beetles, and whiteflies. The smell of the rue confuses these critters, making them less likely to hang around your tomato plants.
Plus, rue is a hardy plant that can withstand heat and drought, so it won’t wilt when the weather gets hot.
According to the Acta Horticulturae journal, tomatoes intercropped with rue had a relatively higher yield. Rue also increased the commercial yield of tomatoes by about 26%, making it a beneficial companion plant. (ref)
Growing tomatoes with the right companion plants can make a big difference in your garden. By working together, your plants will create a healthier and more productive garden.
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Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.