The Popular Leafy Green You May Not Want To Plant Near Basil

Have you ever had kale pesto? The fresh, sweet, and fragrant basil blends beautifully with the earthy and slightly peppery flavor of kale. It's natural to try the traditional basil pesto with a boost of nutrients and layers of flavors of kale. In the kitchen, the two leafy greens pair wonderfully. However, in the garden, they are far from a perfect match. In fact, basil and kale are not good companion plants at all.

The problem lies in the opposite growing conditions. Basil (Ocimum basilicum) needs warm weather and plenty of sun (about 6 to 8 hours of direct sunlight) to grow, and it grows best in USDA zones 10 to 11. Additionally, if you want to ensure a bountiful basil harvest, the soil should be moist but well-drained. Basil produces its highest concentration of essential oils, such as linalool and eugenol, when soil temperatures remain between 65 and 75 degrees Fahrenheit. These oils are what give basil its intense fragrance and flavor. The plant is not tolerant to frost, so you'll need to cover it or find other ways to protect it.

Kale (Brassica oleracea var. acephala), in contrast, prefers cool weather. Kale grows best in temperatures between 40 and 70 degrees Fahrenheit, in moist, well-drained soil. In fact, kale can improve in flavor if it is exposed to light frost. Because kale is hardy and frost-tolerant, it does not do well with the heat-loving basil. So, planting them together is not a great idea.

Basil and kale are both rewarding crops to grow. However, pairing them in the same bed just creates unnecessary challenges. For example, basil is highly susceptible to fungal issues, such as downy mildew and Fusarium wilt. And kale is prone to pests, including aphids, flea beetles, and cabbage worms. Growing them side by side increases the risk of overlapping pest problems, which can quickly spread through a crowded garden. Keeping them apart lets you manage these issues more effectively.

Instead of giving yourself trouble and forcing basil and kale together, consider planting them with better companion plants that will help them thrive. Basil thrives when planted near warm-season crops, such as tomatoes, peppers, oregano, and beans. Tomatoes, especially, make for great companion plants for basil. Basil also grows well indoors in pots. So, you can grow them in a pot in winter, which allows them to soak up the sun without facing freezing conditions.

Kale, on the other hand, pairs well with crops that prefer cool and moist conditions. Celery, cucumber, and spinach grow comfortably in the same environment. Kale's frost tolerance allows it to extend your garden harvest into fall and winter. If you want to maximize your space, a simple rule of thumb is to group basil with vegetables and herbs that can take the heat, and plant kale with cool-season crops. This way, both plants deliver strong and flavorful harvests without compromise.