If you’ve been struggling to get good harvests from your tomatoes despite following the basics of growing vegetables, companion planting might be worth a try. While the jury is still out on how effective companion planting is, there is plenty of anecdotal evidence suggesting that many gardeners have had great success with it.
This guide offers practical advice on companion planting with tomatoes, explaining which plants and conditions work well with them.
I’ve been growing tomatoes for many years and have experimented with companion planting extensively. Here, I’d like to share my experiences and some of the methods that have worked well for me.
What is Companion Planting?
Companion planting is the practice of growing different plants together in a way that helps them both. This gardening method imitates natural systems, where different plants coexist and support one another. By selecting specific plant combinations, we can create a more healthy and productive garden.
Some mechanisms of companion planting are not well understood, such as the claim that apple trees produce better apples when chives are planted nearby. However, we can still rely on anecdotal evidence and personal experience to help guide us.
Companion planting can involve various approaches, including:
- Polyculture: Growing multiple types of plants together to mimic the diversity of natural ecosystems.
- Intercropping: Planting different crops in proximity to each other to maximize space and resource use.
Benefits of Companion Planting
- Sacrificial Plants: These plants attract insects away from your crops, protecting them from damage.
- Attracting Pollinators: Some plants attract pollinators, which help increase crop yields.
- Pest Control: Certain plants attract predators that will eat garden pests, reducing the need for pesticides.
- Weed Suppression: Ground covers and other plants can help suppress weeds by shading the soil and outcompeting weed seedlings.
- Microclimate Improvement: Tall plants can provide shade for smaller plants in hot climates, reducing evaporation.
- Soil Health: Certain plants improve soil structure and health, such as legumes that fix nitrogen, improving the soil for nearby plants.
- Disease Prevention: Increased biodiversity can reduce the spread of diseases by breaking the life cycle of pathogens.
Holistic Garden Management
In addition to the benefits of companion planting, effective pest and disease management is essential for maintaining healthy tomato plants. Crop rotation, where tomatoes are planted in different areas each year, can help prevent the build-up of pests and diseases in the soil.
Additionally, monitoring is essential to quickly identify and rectify any pest or diseases before they can take hold of your garden. By incorporating these pest management strategies alongside companion planting, gardeners can create a resilient and thriving garden resulting in good tomato harvests.
Top 5 Companion Plants for Tomatoes
Spinach
Spinach takes the top spot for me when companion planting with tomatoes. We eat a lot of spinach, so it’s one of the main crops I aim to grow every year. Spinach has a shallow root system, while tomatoes have deep root systems. This means that although both are heavy feeders, they absorb nutrients at different soil layers, allowing you to give them a similar amount of fertilization without competition.
Although they feed at different levels, spinach tends to grow larger and spread so I like to space them a hands width away from the tomato plants.
Both spinach and tomatoes have similar requirements for water, nutrients, and sunlight, making them natural companions. Spinach grows low to the ground, while tomatoes can be trained to grow upward, maximizing the available space. This allows you to grow more crops in the same area where tomatoes would normally take up a lot of space.
Basil
Another favourite of mine, basil is great in the kitchen and often comes highly recommended to be planted with tomatoes. Both plants thrive under similar conditions, and some gardeners swear that basil enhances the flavour of tomatoes. Personally, I haven’t noticed a difference in flavour, but it might be worth trying out for yourself.
Basil’s strong fragrance helps hide the smell of tomatoes from pests like aphids and whiteflies. When mass-planted around tomatoes, basil can also help to hide the tomato plants from pests, providing an extra layer of protection.
Another advantage of planting basil near tomatoes is its role in improving pollination. Basil creates a lot of flowers as it matures and so attracts beneficial insects such as bees, which can increase the pollination of tomato flowers and potentially increase the amount of fresh, red tomatoes on your plants.
I plant basil in any decently sized gaps in the bed, but constantly pick the leaves to keep them small and bushy.
Marigold
While not particularly useful as a crop for your kitchen, marigolds are highly recommended as companion plants for tomatoes. They are incredibly hardy, often self-seeding and requiring little maintenance.
In terms of spacing, because marigolds are small flowers, precise spacing isn’t critical. However, planting them intermittently among your tomato plants can provide good coverage throughout the garden.
One unique benefit marigolds provide is their ability to repel nematodes, organisms that live in the soil that can damage tomato plants.
Their large, fragrant, and attractive flowers attract many beneficial insects, such as pollinators, into your garden while repelling pests like aphids and whiteflies. This not only helps with the pollination of your tomatoes but also enhances the overall health and biodiversity of your garden.
Furthermore, marigolds can attract predatory insects like ladybugs and parasitic wasps, which help control pests, especially aphids, which are a common problem for tomatoes.
In their research, R. Krueger et al. provide valuable insights suggesting that marigolds can help reduce certain types of soil-borne diseases, making them a valuable companion plant for maintaining healthy garden soil. While they might not be useful in a commercial setting or for severe problems, for the backyard gardener they may have some application.
Lettuce
Similar to spinach, Lettuce is a fast-growing, shallow-rooted plant that can be planted underneath the canopy of tomatoes about a hands width away. The canopy of the tomato plant can be beneficial for the lettuce in warmer weather. Lettuce matures quickly and can provide ground cover to help suppress weeds and retain soil moisture.
In my experience it can be a little more fussy to manage than spinach and so gets a lower ranking on the list, but if you prefer the sweet, moist leaves over spinach then this can be a great crop to plant with tomatoes.
Lettuce does tend to bolt in hot weather which tomatoes thrive in, so if you do intend to plant them together make sure you have a shade cloth over the garden bed to help prevent this.
Thyme
Another Mediterranean herb on the list, thyme has culinary uses and works very similarly to basil. Its extremely fragrant aroma helps mask the scent of tomatoes, reducing the pressure from pests. Additionally, thyme’s dense and low growth habit can act as a living mulch, helping to suppress weeds and retain soil moisture.
Given its growth habit, It’s a good idea to give thyme more room to grow. I give thyme a larger spacing of around 30cm from the nearest tomato to avoid any overcrowding issues. While it’s good to have ground cover, you also want air to get to the tomatoes to help reduce disease.
Thyme is also known to attract beneficial insects such as bees and predatory wasps, which can help improve pollination and control pest populations. Its hardiness and low maintenance make it a nice addition to your garden, particularly when planted near tomatoes.
Conclusion
Companion planting is a method you can use to replicate natural systems and improve your garden’s productivity and biodiversity. By strategically planting crops like spinach, basil, marigolds, lettuce, and thyme with your tomatoes, you can create a more natural and resilient growing environment. These companion plants offer benefits such as pest control, improved pollination, and soil health, making them excellent choices for any gardener looking to optimize their tomato harvest.
In combination with holistic management practices, such as crop rotation and proactive pest monitoring, companion planting can further enhance the health and productivity of your garden.
Have you tried companion planting with your tomatoes? What has been your experience? Share your thoughts and tips in the comments below – I’d love to hear about your successes and challenges with companion planting!
