Tomatoes don’t like being alone! Contrary to what most gardeners think, tomatoes actually thrive surrounded by other plants. The trick is knowing which plants enhance their flavor, deter pests, and enrich the soil, as well as knowing which plants to avoid who steal nutrients and encourage chaos.
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Check PriceThe Science Behind Companion Planting with Tomatoes
Smart companion planting works because plants use both above- and below-ground channels to communicate and share both positive and negative effects on other plants. Each plant is known to release and receive different “messages” and “command” varying effects on nearby plants and soil. For example, some release “send” and “confuse” pests while others “improve” soil structure and “control” pests. For instance, tomatoes do especially well when paired with companion plants that are able to provide similar growing conditions but offer different “services” in return.
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9 Perfect Tomato Companions
1. Basil – The Flavor Enhancer
Basil doesn't just taste great with tomatoes; it actually improves the flavor of tomatoes when grown nearby. Plant basil among your tomatoes to repel aphids, spider mites, hornworms, and to increase the concentration of essential oils that make your tomatoes taste better.
2. Marigolds – The Pest Patrol
French marigolds (Tagetes patula) can protect your garden from dangerous soil insects, like nematodes and whiteflies, and other pests. For the best defense, plant them around your tomato patch and even between your tomato plants. The flowers of French marigolds are also attractive to good predatory insects.
3. Nasturtiums – The Best Trap Crop
These edible flowers serve as decoys. They're able to entice aphids, cucumber beetles and squash bugs away from your tomatoes. You can plant nasturtiums around your tomato plants, and let them trail around the tomato cages. On top of that, the flowers are peppery and add color to your salad.
4. Carrots – The Allies Below Ground
Carrots help soil drainage near tomato plants by breaking up compacted soil with their taproots. They grow well in the shade created by the tomatoes and they are ready for harvest before the root systems start competing. The ferny foliage of carrots also helps with soil moisture retention.
5. Parsley – A Magnet For Beneficial Insects
Hoverflies, parasitic wasps, and other helpful insects that feed on tomato pests are attracted to both flat-leaf and curly parsley. For this reason, plant parsley as a living mulch around the bases of your tomatoes or in adjacent rows. It will tolerate the same watering schedule and will not compete for space.
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6. Chives – The All-Around Assistant
Chives can repel aphids and can increase flavor in tomatoes. Chives can also attract pollinators with their pretty purple flowers. They can be used as a border perennial around a tomato bed. The onion smell of chives confuses pest insects. Additionally, chives can be harvested all season and it won't hurt the plant.
7. Borage – The Soil Improver
The leaves of this herb accumulate potassium and calcium which are made available to the soil when the leaves decompose. It also attracts bees to help pollinate the tomatoes and may even increase the plants' resistance to disease. Plant it next to your tomato beds and allow some leaves to fall as a natural mulch.
8. Oregano – The Disease Fighter
The pungent smell released from oregano can help stop fungal diseases that target tomatoes. Their low-growing habit is great for use as living mulch around tomato plants. Make sure to frequently harvest oregano leaves to maintain bushy and productive plants throughout the entire season.
9. Lettuce – The Space Maximizer
Lettuce grows well between young tomato plants and helps to make good use of space. Lettuce will be ready to harvest before the tomatoes need the space, plus lettuce has shallow roots which won't compete with the deeper roots of the tomatoes. For best results, choose varieties that are tolerant to heat.
3 Plants That Harm Tomatoes
Fennel – The Chemical Warfare Expert
Fennel is known to inhibit the growth of tomatoes and may even stunt the growth of surrounding plants. Its tall growth and aggressive root systems also compete for nutrients and space. For these reasons, fennel should be kept separated from all nightshade family plants in the garden.
Walnut Trees – The Silent Killers
The Black walnut tree gives off a chemical called juglone, a natural herbicide that is highly toxic to tomatoes. It can even kill other nearby plants that are within the root zone of the walnut tree. Do not plant tomatoes within 50 feet of walnut trees. Do not use walnut sawdust or walnut leaves as mulch in your tomato garden.
Corn – The Resource Hog
Corn is not directly harmful to tomatoes but it does take some of the nutrients and water that the tomatoes need. Both plants are very nutrient thirsty which makes them poor companions in the garden. Also, the height of corns creates unwanted shade for tomatoes which need full sun.
Timing Your Companion Plants
When planting, the type of plants chosen isn’t as important as the spacing, timing, and the plants chosen. Direct sow lettuce and carrots about 2-3 weeks before the last expected frost. For best germination of marigolds and nasturtiums, wait until the soil warms to plant them. Also, transplant basil, oregano, and parsley at the same time as your tomatoes so they can establish themselves quickly.
Setting Up for Success
Instead of planting individual diverse plants, try to create communities of compatible plants. Use herbs as living borders around tomato beds, and try to put together plants that have the same needs in terms of water, nutrients, and frequency of irrigation. Also, more nutrients in soil means that the plants will grow better together, so mix a lot of compost into the soil before you plant, and add mulch to the top of the soil around the established plants to trap moisture in the soil and keep the weeds from taking over.
Growing tomatoes in the garden is a thoughtful process. It requires planning for cooperative companion planting that builds tomato soil and keeps harmful pests and competitive plants away. This way your garden works and produces more than the expected amount of tomatoes harvest.
