Garden Vegetable Garden Ideas 10 Plants You Should Never Grow Next to Your Tomatoes Gardening experts share advice to make sure your tomatoes thrive where you plant them. By Felicia Feaster Felicia Feaster Felicia Feaster has worked for the past 20-plus years as a lifestyle journalist. She specializes in writing about interior design, gardening, trends, culture, travel, and wellness. Editorial Guidelines Published on May 18, 2024 Close Photo: Westend61 / Getty Images While tomatoes are a summer garden staple, the amount of fretting and fear involved in growing them may put them in the ranks of plants that can be challenging for even experienced gardeners. But there is no reason for backyard farmers to fear. If you want to give your tomatoes a fighting chance, there are things you can do to give them a solid head start. Growing disease-resistant tomato varieties, getting enough sun, and regular watering are all good bedrock for growing healthy tomatoes, for instance. But another critical step in ensuring your tomatoes have the best chance of growing happy and healthy is thinking not just about where you plant them but what you plant them next to. While certain companion plants for tomatoes help this plant thrive, other plants and vegetables should be planted elsewhere because they can inhibit healthy tomato growth. Ahead, our experts explain which plants can actually hinder your tomato plant's growth if planted too close together in your garden. Carrie Spoonemore, co-creator of Park Seed’s From Seed to Spoon app Kelly Smith Trimble, gardening expert and author of two books on vegetable gardening, Vegetable Gardening Wisdom and The Creative Vegetable Gardener Your Guide to Growing Tomato Plants From Seeds 01 of 10 Fennel Fennel is not a good companion for any garden crop. dagut / Getty Images Allelopathic plants release toxins into the soil that inhibit the growth of other plants, in a sense eliminating their competition. An allelopathic plant like fennel can directly impact tomato growth, says Carrie Spoonemore, co-creator of Park Seed’s From Seed to Spoon app, so she recommends gardeners not plant it near tomatoes. 14 Vegetables You Should Never Plant Together—Gardening Experts Explain Why 02 of 10 Cabbage Getty Images Cabbage and other plants in the brassica family can compete with tomatoes for vital nutrients in the soil, says Spoonemore, thus robbing tomatoes of an ideal growing medium. In addition, cabbage also has a wide growing habit that can crowd tomato plants out. 03 of 10 Pole Beans Neyya / Getty Images Avoid pole beans near your tomatoes—they can grow aggressively and end up shading your tomatoes too much. "While some companion planting guides suggest planting pole beans with tomatoes, there is a risk of competition for sunlight, water, and nutrients, especially if the beans grow vigorously and shade the tomato plants excessively," says Spoonemore. 04 of 10 Dill Oxana Medvedeva / Getty Images Herbs are often ideal companion plants for tomatoes, but dill is the exception. Mature dill plants can harm tomato plants, taking soil nutrients for themselves and inhibiting tomato root growth. 3 Reasons Your Tomatoes Aren't Turning Red—and 4 Ways to Help Them Ripen 05 of 10 Corn Westend61 / Getty Images Corn belongs to a group of vegetables that should not be planted close to tomatoes because, once grown and tall, they can shade tomatoes out and inhibit their growth. Experts Explain Why Tomatoes Split, Plus Tips for Prevention 06 of 10 Okra Jenny Dettrick Until you’ve grown okra, you might not expect the towering growth habit and lovely pale yellow hibiscus-like flowers this Southern vegetable produces. Planting okra next to tomatoes isn't encouraged because its leafy height could keep tomatoes from getting their required 6 to 8 hours of sun a day. 07 of 10 Potatoes Getty Images Kelly Smith Trimble, a gardening expert and book author on the subject, recommends not planting potatoes near tomatoes. Potatoes are in the same Solanaceae (or nightshade) family as tomatoes, meaning that both plants are susceptible to the same pests and diseases. How to Grow and Care for Potatoes—Including Martha's Favorite Planting Method 08 of 10 Broccoli Barbara Rich / Getty Images Some vegetables, like broccoli, are known as "heavy feeders" in the garden world, meaning they require rich soil with plenty of nutrients to grow. For that reason, broccoli should not be planted close to tomatoes to ensure your tomatoes have the nutrients they need to thrive. How to Grow Broccoli Plants in Your Own Backyard, No Matter the Season 09 of 10 Cauliflower tc397/Getty Images Cauliflower attracts pests like cabbage worms and aphids that can also attack tomato plants. In addition, cauliflower is a heavy feeder that can sap the soil of vital nutrients. 10 of 10 Eggplant Yuliia Bilousova Tomatoes and eggplants are in the same nightshade family, and as a result, eggplant will compete with tomatoes for nutrients. Eggplants can also spread blight, a fungal disease spread by insects, wind, water, and animals that is especially prevalent among potatoes and tomatoes. You will know if your tomatoes have been exposed to blight if you see browning, rotting fruit, and shriveled leaves on your plants. How to Stake and Cage Tomato Plants, According to Martha’s Head Gardener Was this page helpful? Thanks for your feedback! Tell us why! 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