Planting basil next to tomatoes is one of the most popular and effective examples of companion planting. These two plants thrive in the same conditions—full sun, warm temperatures, and well-draining soil—making them ideal neighbors in both garden beds and containers.
Key Benefits of This Pairing
- Natural Pest Control: The strong aromatic oils in basil help repel common tomato pests like aphids, whiteflies, spider mites, and mosquitoes. It is also famously known to deter the tomato hornworm.
- Improved Pollination: Basil flowers are a magnet for bees and other beneficial insects, which helps ensure higher pollination rates and better fruit set for your tomatoes.
- Flavor Enhancement: While scientific evidence is mixed, many gardeners swear that growing basil near tomatoes improves the flavor and aroma of the fruit.
- Shade and Moisture: Tall tomato plants provide beneficial afternoon shade for more delicate basil leaves, helping to keep the soil cool and moist for the water-loving herb.
How to Plant Them Together
- Timing: Wait until the soil temperature is at least 60°F (15.5°C) before planting both. This usually coincides with the time you would transplant tomatoes after the last frost.
- Spacing: Plant basil starts or seeds approximately 10–12 inches (25–30 cm) away from the base of your tomato plants. This ensures enough space for air circulation to prevent fungal diseases like downy mildew.
- Proportions: For the best protective results, some experts recommend planting three basil plants for every one tomato plant.
- Container Tips: If growing in a pot, use at least a 5-10 gallon container. Place the tomato in the centre and tuck the basil along the outer edge
What to Avoid
- Fennel: Never plant fennel near this duo, as it releases chemicals that can inhibit the growth of both tomatoes and basil.
- Cabbage Family: Broccoli, kale, and cauliflower can compete heavily for the same nutrients and may stunt tomato growth.
- Dill: While many herbs are good, mature dill can eventually stunt tomato root growth.
