Companion plants that grow well with tomatoes
Tomatoes thrive when planted alongside certain vegetables, herbs, and flowers that improve soil health, repel pests, or make better use of garden space. The best companions are plants that don't compete for the same nutrients or root depth, and that either attract beneficial insects or keep harmful ones away. Basil, carrots, parsley, and marigolds are the most reliable choices for most gardeners.
Companion planting works because different plants have different needs. A shallow-rooted herb like basil won't fight a tomato's deeper roots for water and nutrients. A flower like marigold attracts pollinators and repels certain pests without needing the same soil conditions. The goal is to create a small ecosystem where each plant makes the garden better for the others.
Key Takeaways
- Basil planted near tomatoes improves flavor, repels spider mites and flies, and uses less water than the tomato plant itself.
- Root vegetables like carrots and beets grow below tomato roots and won't shade the plant or compete for surface nutrients.
- Marigolds and nasturtiums draw pests away from tomatoes by attracting them to the flowers instead, reducing the need for sprays.
- Avoid planting tomatoes near brassicas (cabbage, broccoli), fennel, or potatoes, which compete for nutrients or attract the same pests.
- Herbs like parsley, oregano, and thyme improve soil and attract pollinators without shading or crowding the tomato plant.
Herbs that pair well with tomatoes
Basil is the classic tomato companion. It grows to a similar height but stays bushy and low, so it won't shade your tomatoes. Basil repels spider mites, whiteflies, and some beetles that damage tomato leaves. Plant it at the base of the tomato cage or 6 to 12 inches away. Basil also needs less water than tomatoes, so it won't dry out the soil around the roots.
Parsley is a shallow-rooted herb that won't compete with tomato roots. It attracts hoverflies and parasitic wasps, both of which eat aphids and other soft-bodied pests. Plant parsley 12 inches from the tomato stem. It tolerates partial shade from the tomato plant, so it's useful in tight spaces.
Oregano and thyme are low-growing perennials that improve soil structure over time. They don't need much water or fertilizer, so they won't drain resources from your tomatoes. Both attract pollinators and beneficial insects. Plant them 18 inches away to give the tomato room to spread.
Vegetables and root crops to plant with tomatoes
Carrots and beets grow below the soil surface and have roots that stay in the top 8 to 10 inches of soil. Tomato roots go deeper, so there's little competition. These root vegetables also don't shade the tomato plant. Space carrots 3 to 4 inches from the tomato stem and thin them as they grow so they don't crowd the base.
Onions and garlic repel spider mites and some beetles. They also have shallow roots and won't compete with tomatoes for deep water and nutrients. Plant onions 6 to 8 inches away and garlic 12 inches away. Both are slow-growing, so they won't shade the tomato plant during its critical early weeks.
Lettuce and spinach are cool-season crops that grow in the shade of a tomato plant once the tomato is tall enough. They mature quickly (30 to 45 days) and can be harvested before the tomato plant fully leafs out. Plant them 12 to 18 inches from the stem so they have room to spread without touching the tomato.
Flowers that protect tomatoes from pests
Marigolds are the most popular pest-control flower for tomatoes. They attract spider mites away from tomato leaves and draw beneficial insects that eat aphids and whiteflies. Plant marigolds 12 to 18 inches from the tomato stem. They need full sun and well-draining soil, so they won't compete with tomatoes for water in most gardens.
Nasturtiums act as a trap crop—pests prefer them to tomatoes, so they feed on the nasturtium instead. Plant nasturtiums 18 to 24 inches away where they can spread without shading the tomato. They also attract pollinators. Nasturtiums tolerate poor soil, so they won't drain nutrients from the tomato bed.
Borage is a tall herb with blue flowers that attract pollinators and parasitic wasps. It can grow 2 to 3 feet tall, so plant it on the north side of tomatoes so it doesn't shade them. Borage also improves soil structure as it breaks down. Space it 24 inches away to give it room to spread.
Plants to keep away from tomatoes
Avoid planting tomatoes near brassicas (cabbage, broccoli, cauliflower, and kale). Both tomatoes and brassicas are heavy feeders that pull nitrogen from the soil quickly. They also attract some of the same pests, so planting them together increases pest pressure on both crops. Keep brassicas at least 3 feet away.
Fennel releases a chemical into the soil that slows the growth of most nearby plants, including tomatoes. It also attracts different pests and pollinators, so it doesn't add to the ecosystem. Plant fennel in a separate bed at least 4 feet away.
Potatoes are in the same plant family as tomatoes (Solanaceae) and attract the same pests, especially the Colorado potato beetle and early blight fungus. Planting them together doubles the pest and disease pressure. Keep potatoes at least 3 feet away or in a different garden bed entirely.
How to arrange companion plants around tomatoes
Start by planting your tomato in the center of its space. If you're using a cage or stake, plant basil at the base (6 to 12 inches away) where it will stay in the tomato's shadow as the plant grows. Plant shallow-rooted herbs like parsley and oregano 12 to 18 inches away in a circle around the tomato. This creates a ring of pest-repelling plants without crowding the main stem.
Place root vegetables like carrots and beets 12 to 18 inches away, spacing them according to their mature size. Marigolds and nasturtiums go on the outer edge, 18 to 24 inches away, where they have room to spread and won't shade the tomato. If you're planting lettuce or spinach, put them on the north side of the tomato so the tomato plant shades them as it grows taller.
Water all plants together if they're in the same bed, but remember that basil needs less water than tomatoes. If basil starts to wilt while tomato soil is still moist, move it slightly farther away or mulch around it to retain moisture. Check spacing every two weeks as plants grow—thin or move companions if they start to crowd the tomato stem.
Frequently Asked Questions
Can I plant multiple tomatoes with the same companion plants?
Yes, but space each tomato at least 24 to 36 inches apart so they don't shade each other. You can plant one ring of companions around each tomato, or create one larger bed with multiple tomatoes and companions spaced throughout. The key is making sure each tomato gets at least 6 to 8 hours of direct sun and has room for air to flow around its leaves.
Do I need to plant companions every year?
Companion planting works year to year, but the soil benefits build over time. Herbs like oregano and thyme are perennials and will return the next season. Basil, marigolds, and nasturtiums are annuals and need to be replanted each year. Rotating which companions you plant in the same spot every few years keeps soil balanced and prevents pest buildup.
What if I don't have space for companion plants?
Tomatoes grow fine alone, especially if you're growing just one or two plants in a container or small bed. Companion planting is most useful when you're growing multiple tomatoes or dealing with recurring pest problems. If space is tight, focus on basil—it takes up minimal room and provides the most noticeable benefits for flavor and pest control.
Can I plant companions in containers with tomatoes?
Yes, but use a container at least 18 to 24 inches wide so roots have room. Plant the tomato in the center and basil or parsley around the edge. Avoid root vegetables in containers because they need more depth. Water more often in containers since they dry out faster than garden beds.
Will companion plants reduce my tomato harvest?
No. Companion plants actually increase tomato yield by reducing pest damage and improving pollination. The space they take up is minimal compared to the tomato plant itself, and they don't compete for the nutrients the tomato needs most. In most cases, gardeners with companions get more usable tomatoes than those growing tomatoes alone.