What to Plant With Tomatoes
The best tomato companions are basil, marigold, nasturtium, parsley, dill in flower, onions, and carrots. Keep tomatoes away from potatoes, corn, and blac...
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What to Plant With Tomatoes
Plant basil, marigold, and flowering herbs such as dill and parsley near tomatoes. Carrots, onions, and garlic fit in the gaps. Keep tomatoes away from potatoes, corn, and black walnut trees.
Check any pair on the Companion Planting Desk. It marks which pairings have research behind them.
Good Tomato Companions
- Basil. Some evidence. A few field and greenhouse studies found fewer thrips on tomatoes interplanted with basil. There is no good evidence that basil changes tomato flavor. Plant it at the edge of the cage so it gets sun.
- Marigold. Some evidence. Trials found fewer thrips on tomatoes with marigolds nearby. For root-knot nematodes, a few marigolds in the row do little. Marigold only helps as a dense stand grown for 2 months or more in the same spot before the tomatoes.
- Dill, parsley, and cilantro in flower. Evidence-backed for beneficial insects. Their small flowers feed hover flies and parasitic wasps that attack aphids and hornworms. Let a few plants bolt. Pull dill before it gets big and shades young tomatoes.
- Borage, zinnia, and cosmos. Some evidence. Flowers bring pollinators and predators into the bed. They will not fix a pest problem on their own.
- Carrots, onions, garlic, and chives. Traditional. They take little room and finish at different times, so they use space well. There is little testing on direct benefits to tomatoes.
- Lettuce and spinach. Traditional, but a smart use of space. Plant them in spring before tomatoes fill in, and harvest before the canopy closes.
Keep These Away From Tomatoes
- Potatoes. Evidence-backed. Same family. They share late blight, early blight, and Colorado potato beetle. Keep them in separate beds and rotate both.
- Corn. Evidence-backed. Corn earworm and tomato fruitworm are the same insect. A corn patch can build up moths that move to tomatoes.
- Black walnut. Evidence-backed. Walnut roots release juglone, and tomatoes are among the most sensitive plants. Keep tomatoes 50 to 60 feet from a mature tree.
- Strawberries and raspberries. Evidence-backed. Tomatoes host verticillium wilt, which kills berries. Do not plant berries where tomatoes grew in the last 3 to 5 years.
- Cabbage family and fennel. Traditional. Common chart advice with little testing. Both cabbage and tomatoes are heavy feeders, so give each enough room and fertility.
Spacing Still Comes First
A good companion will not help a crowded tomato. Give each plant the spacing on its plant page, at least 6 hours of sun, and steady water. Tuck companions at the edge, not under the leaves where they stay wet.
Quick Plan for One Tomato Bed
- Plant tomatoes on the north side of the bed so they do not shade shorter crops.
- Set basil and a few marigolds along the south edge.
- Sow carrots or onions in the open spaces between cages.
- Let one or two dill or parsley plants flower at the end of the bed.
- Next year, move the tomatoes. See the Crop Rotation desk.
See also plants that should not be planted together and companion planting myths vs evidence.
Sources: University of Minnesota Extension, Companion planting in home gardens; University of Florida IFAS, Marigolds for Nematode Management; University of Wisconsin Extension, Black Walnut Toxicity.