Tomatoes are among the most rewarding crops to grow, but their success often depends on more than just sunlight and water. By choosing the right companion plants—and knowing which ones to steer clear of—gardeners can dramatically boost their harvests, improve flavour, and protect their crops from common threats. In this article, we explore the best and worst planting partners for tomatoes, why companion planting works, and how to adapt these techniques whether you’re using pots, a greenhouse, or a traditional garden plot.
🌿 Quick take: what you’ll learn about tomato companions
- 🥬 The best plants to grow with tomatoes to repel pests and boost flavour
- 🌼 Which flowers and herbs act as living pesticides (and pollinator magnets)
- 🚫 The common crops that can ruin your tomato yield if grown too close
- 🪴 How to choose companions based on whether you garden in pots, greenhouses, or allotments
Fun fact: Tomatoes and carrots might not mix well on a dinner plate, but in the garden, carrots help break up the soil for tomato roots to breathe and grow deeper.
Why companion planting works
Companion planting is more than an old gardener’s tale—it’s a proven method of using plant relationships to improve health, yield, and resilience. For tomatoes, a number of herbs, vegetables, and flowers have natural properties that either deter pests, enrich the soil, or attract pollinators. This ecological balance not only supports tomatoes but creates a more productive, self-sustaining garden.
Tomato’s dream team
Some plants are practically made to grow alongside tomatoes. Basil tops the list, enhancing the flavour of tomatoes while repelling insects like aphids and hornworms. Marigolds are a vibrant ally, known to deter nematodes in the soil and attract bees. Garlic and chives release sulphur-based compounds that fend off fungal diseases and many pests.
Other reliable companions include nasturtiums, which act as a trap crop to lure aphids away from your tomatoes, and borage, which attracts pollinators and repels tomato hornworms. Even lettuce plays a role—it acts as a natural ground cover, helping retain moisture and suppress weeds.
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Plants to keep away
Just as some plants help tomatoes thrive, others can severely hinder them. Fennel is notorious for releasing compounds that stunt tomato growth. Brassicas—such as cabbage, kale, and broccoli—compete for nutrients and don’t mix well in the same bed. Potatoes should also be avoided, as they are in the same family as tomatoes and share diseases like blight, which can spread quickly between the two.
Companions for pots, plots, and greenhouses
Companion planting isn’t one-size-fits-all. In pots or small raised beds, opt for compact herbs like thyme, basil, and parsley that won’t compete for root space. In greenhouses, where air circulation can be limited, avoid overcrowding—choose plants that support airflow and deter greenhouse pests, such as marigolds or nasturtiums. On allotments or larger garden beds, spacing becomes easier, and you can incorporate taller plants like borage or edible borders with lettuce and carrots.
Managing pests the natural way
One of the major benefits of companion planting is the natural pest control it provides. By avoiding synthetic pesticides, you not only protect your plants but also the beneficial insects that help keep your garden balanced. Ladybirds, bees, and hoverflies are drawn to many companion flowers, while the pungent smells of garlic and chives keep pests at bay. It’s a win-win for gardeners looking to grow healthy tomatoes in a more eco-friendly way.
Rotation and maintenance tips
To make companion planting effective year after year, crop rotation is key. Avoid planting tomatoes in the same spot every season, as this can lead to soil fatigue and recurring diseases. Also, monitor your garden regularly for signs of pest infestations or overcrowding. Water consistently, especially during hot months, and prune nearby companions if they begin to overshadow your tomato plants. With proper care, companion planting becomes one of the most powerful tools in your gardening toolkit.
Let your garden work smarter
Companion planting allows gardeners to tap into the natural intelligence of plants—creating a cooperative environment where each plant plays a role. By pairing tomatoes with the right allies, and avoiding known adversaries, it’s possible to boost flavour, reduce pest problems, and grow healthier crops with less effort and fewer chemicals. Whether you’re growing in a pot on your balcony or managing an expansive allotment, thoughtful plant pairings can transform the way you garden.
Come back soon for more practical tips and seasonal insights to help you get the most from your garden!
