Corn: Both tomatoes and corn are heavy feeders, competing for nutrients in the soil. Additionally, corn attracts tomato fruitworms, which can damage tomato plants.
Potatoes: Potatoes and tomatoes are both susceptible to similar diseases, such as late blight and early blight. Planting them together increases the risk of disease transmission.
Cabbage and Broccoli: These brassica family plants can release chemicals into the soil that inhibit tomato growth and may stunt their development.
Fennel: Fennel excretes chemicals that inhibit the growth of nearby plants, including tomatoes. Planting them together can result in poor growth and yield for both crops.
Walnuts: Walnut trees and tomato plants produce juglone, a toxic chemical that can inhibit the growth of many plants, including tomatoes.
Kohlrabi: Kohlrabi can compete with tomatoes for nutrients and water in the soil, leading to reduced growth and yield for both crops.
Dill: Dill attracts tomato hornworms, which can devastate tomato plants if left unchecked. Planting dill near tomatoes may increase the risk of hornworm infestation.
Rue: Rue releases chemicals that can inhibit the growth of nearby plants, including tomatoes. Avoid planting rue near tomatoes to prevent negative effects on tomato growth and yield.
Cucumbers: While some gardeners believe that tomatoes and cucumbers can be compatible companions, others suggest that cucumbers may compete with tomatoes.