Tomatoes are a must-have in many home gardens—but did you know that the plants growing nearby can make or break your harvest? While some companions, like basil, help tomatoes thrive, others can hinder their growth, attract pests, or spread diseases.
Understanding which vegetables not to plant near tomatoes can help you avoid stunted plants, low yields, and garden headaches. Let’s take a look at 10 vegetables that are bad neighbors for tomatoes—and why you should keep them far apart.
🌿 What Is Companion Planting?
Companion planting is the practice of grouping plants together based on how well they support each other’s growth. Some combinations improve soil nutrients, repel pests, and even boost flavor. But not all plants get along—and tomatoes are particularly picky neighbors.
🍅 Why Tomatoes Need the Right Companions
Tomatoes are heavy feeders with large root systems and high nutrient needs. They also need good airflow and sunlight to stay healthy. Planting the wrong vegetables nearby can:
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Compete for nutrients like nitrogen and potassium
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Encourage the spread of pests and fungal diseases
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Block sunlight or limit air circulation
By choosing the right garden layout, you’ll set your tomatoes up for success.
❌ 10 Vegetables to Avoid Planting Near Tomatoes
1. Fennel
Fennel is the worst neighbor you could give your tomatoes. It produces allelopathic chemicals—natural compounds that inhibit the growth of nearby plants, especially tomatoes. Fennel should always be planted in its own separate bed.
2. Cabbage Family (Broccoli, Cauliflower, Brussels Sprouts, Kale)
These Brassicas are notorious for stealing nutrients, especially nitrogen, from the soil—nutrients tomatoes desperately need. They also attract aphids and cabbage worms, which can easily migrate to your tomatoes. Keep them in a separate area of the garden.
3. Corn
Corn and tomatoes both need a lot of nitrogen and sunlight. When planted together, they compete for resources, leaving both undernourished. Corn can also shade out tomatoes and attract corn earworms—which love munching on tomatoes too.
4. Potatoes
Tomatoes and potatoes are botanical cousins—both part of the nightshade family (Solanaceae)—which means they share many of the same diseases, especially late blight. Planting them together increases the risk of infection and soil-borne issues.
5. Eggplant
Like potatoes, eggplants belong to the nightshade family and are prone to the same pests and diseases as tomatoes, including Colorado potato beetles and verticillium wilt. Keep them apart to avoid spreading problems.
6. Peppers
Peppers may seem like a natural fit, but they too are part of the nightshade family. Planting them close to tomatoes increases the risk of bacterial spot and tobacco mosaic virus, and they’ll compete for the same nutrients and growing space.
