Companion plants grow better alongside tomatoes and help them thrive
The plants you grow next to tomatoes can improve their flavor, protect them from pests, and make better use of your garden space. Companion planting pairs tomatoes with vegetables, herbs, and flowers that either benefit the tomato plant or benefit from growing nearby. Some companions attract helpful insects, others repel pests that damage tomato leaves and fruit, and a few improve soil quality or shade the roots during hot weather.
The best companions are plants that don't compete for the same nutrients or space, and that don't attract the same pests. A tomato plant's root system spreads wide but stays relatively shallow, so deep-rooted plants like carrots work well in the same bed. Herbs like basil and parsley take up little space and actually improve tomato flavor when planted close by.
Key Takeaways
- Basil, parsley, and marigolds are the most reliable companions—basil improves flavor, marigolds repel harmful insects, and parsley attracts beneficial ones.
- Root vegetables like carrots, beets, and onions grow below tomato roots and don't compete for space or nutrients in the upper soil.
- Borage and nasturtiums attract pollinators and trap pests away from tomato plants, reducing the need for sprays.
- Avoid planting tomatoes near brassicas (cabbage, broccoli), fennel, or other nightshade plants, which compete for nutrients or attract the same pests.
- Space companion plants so they don't shade the tomato plant's lower leaves, which need sun to prevent disease.
Herbs that improve tomato flavor and health
Basil is the classic tomato companion and works for both practical and culinary reasons. It repels spider mites, whiteflies, and hornworms—three of the most common tomato pests—while its scent actually enhances tomato flavor when grown nearby. Plant basil 12 inches away from the tomato stem, where it will get full sun but won't shade the tomato's lower leaves. Basil also grows quickly, so you can harvest it regularly without harming the tomato plant.
Parsley and chives attract hoverflies and parasitic wasps, both of which hunt the insects that damage tomato leaves. Plant parsley in clusters around the base of your tomato bed, leaving at least 6 inches between the parsley and the tomato stem. Chives take up even less space and can be tucked into corners. Both herbs tolerate partial shade, so they work well on the shadier side of a tall tomato plant.
Oregano and thyme are low-growing herbs that won't shade tomatoes and attract beneficial insects while repelling some common pests. They prefer drier soil than tomatoes, so plant them slightly uphill or in a raised section of the bed where water drains faster.
Root vegetables that share space without competing
Carrots, beets, and turnips grow downward while tomatoes grow upward and outward, so they occupy different soil layers. Plant carrots in rows between tomato plants, spacing them 3 inches apart. They'll be ready to harvest in 60 to 80 days, well before the tomato plant needs the space. Beets take slightly longer (70 to 100 days) but are equally compatible.
Onions and garlic also work well as tomato companions. They repel spider mites and some fungal diseases, and their roots stay shallow enough not to interfere with tomato roots. Plant onion sets or garlic cloves 6 inches away from the tomato stem. Both will be ready to harvest before or around the same time as your tomatoes, freeing up space in the bed.
Radishes grow so quickly (25 to 30 days) that they're often used as a "marker crop" between slower-growing plants. Plant radish seeds in the spaces between tomatoes, and by the time the tomato plant needs room to spread, the radishes are already harvested.
Flowers that trap pests and attract pollinators
Marigolds are the most widely recommended flower for tomato beds because they repel whiteflies, spider mites, and some soil-dwelling nematodes. Plant them 12 inches away from the tomato stem so they don't shade the lower leaves. Marigolds bloom all season, so they'll protect your tomatoes from early summer through fall. They also self-seed, meaning you may get volunteer marigolds in the same spot next year.
Nasturtiums act as a trap crop—pests prefer them to tomatoes, so the insects congregate on the nasturtiums instead. This works best if you plant nasturtiums around the perimeter of your tomato bed rather than directly next to each plant. Nasturtiums also attract pollinators and are edible, so you can harvest the flowers and leaves for salads.
Borage produces small blue flowers that attract bees and other pollinators, which improves fruit set on tomato plants. It also repels tomato hornworms. Borage grows tall (2 to 3 feet), so plant it on the north side of your tomato bed where it won't shade the plant during the growing season. Borage self-seeds readily, so deadhead spent flowers if you don't want it spreading.
Plants to keep away from tomatoes
Brassicas—cabbage, broccoli, cauliflower, and kale—compete with tomatoes for the same nutrients and attract some of the same pests. Keep them at least 3 feet away. Fennel actually inhibits tomato growth and should not be planted in the same bed at all. Other nightshade plants like peppers and eggplants attract the same pests as tomatoes, so while they can grow nearby, they don't offer the protective benefits of true companion plants.
Potatoes are nightshades and also carry diseases that can spread to tomatoes through shared soil. If you grew potatoes in a bed last year, wait at least two years before planting tomatoes there. Corn and tomatoes compete for nitrogen, so space them far apart or plant them in different beds entirely.
How to arrange companions in your tomato bed
The layout of your companions matters as much as which plants you choose. Tomato plants need full sun on their leaves and good air circulation to prevent fungal disease, so never plant tall companions directly north of a tomato plant where they'll shade it as the sun moves. Instead, place tall companions like borage or basil on the north side of the bed, where they shade the soil but not the tomato leaves.
Space herbs and flowers at least 12 inches away from the tomato stem to avoid crowding the main plant. Root vegetables can be closer—6 inches is fine—because they won't compete for light. If you're planting in rows, alternate tomatoes with companions: tomato, basil, tomato, carrot, tomato, marigold, and so on. This maximizes space while keeping each plant's roots in its own zone.
Water companions on the same schedule as tomatoes if they're in the same bed. Most herbs and root vegetables tolerate the consistent moisture that tomatoes need, but oregano and thyme prefer drier soil, so plant them in a slightly raised section or use drip irrigation to water only the tomato and root vegetable zones.
Timing your companion plantings
Plant fast-growing companions like radishes and lettuce at the same time as your tomato transplants. They'll be harvested before the tomato plant needs the space. Plant slower companions like carrots and beets two to three weeks after transplanting tomatoes, once the tomato plant is established and less likely to be damaged by the disturbance of planting nearby.
Herbs like basil should be planted after the last frost date in your area, at the same time as tomatoes or a week or two after. If you plant basil too early in cold soil, it will sit dormant and may rot. Perennial herbs like oregano and thyme can be planted in spring and will return year after year, so they're a good long-term investment if you plant tomatoes in the same bed annually.
Frequently Asked Questions
Can I plant lettuce and spinach with tomatoes?
Yes. Both are cool-season crops that mature quickly (30 to 50 days), so plant them early in the season and harvest them before the tomato plant gets large. They tolerate partial shade from the tomato plant, which actually helps them stay cool in midsummer. Plant them 6 inches away from the tomato stem.
Do I have to plant companions, or will tomatoes grow fine alone?
Tomatoes will grow alone, but companions reduce pest pressure, improve flavor, and make better use of garden space. Even one or two companions—like basil and marigolds—will noticeably reduce the insects you see on your tomato plant.
What if I'm growing tomatoes in a container?
Container tomatoes have limited root space, so choose only one or two small companions. Basil works well in a 5-gallon pot with a tomato plant. Parsley and chives also fit. Avoid root vegetables in containers because they need deeper soil than a shared pot provides.
Can I plant tomatoes next to beans?
Yes, but with caution. Beans fix nitrogen in the soil, which benefits tomatoes, but they also attract some of the same pests. Plant beans at least 2 feet away and monitor both plants for spider mites and whiteflies. Pole beans work better than bush beans because they take up vertical space rather than spreading across the bed.
Will companion plants reduce the number of tomatoes I harvest?
No. Well-chosen companions actually increase your harvest by reducing pest damage and disease. The space taken by herbs and flowers is more than offset by healthier tomato plants that produce more fruit.