Top 7+ plants you should never grow next to basil
See which plants don't make good neighbors for basil.
Before you add basil (Ocimum basilicum) to your garden, make sure it’s compatible with the plants that will be growing around it. They should have similar light, water, temperature, and soil needs, or one of them will end up struggling. Some plants can also release harmful chemicals that can affect your basil crop. It’s best to choose plants that complement one another when grown together. Companion plants can deter pests, improve soil, provide shade, suppress weeds, and attract insects that help each other grow. Before you prep your garden, check out which plants you should not grow next to basil.
What Basil Needs To Grow
When planting basil in the garden, keep its growing requirements in mind to see what plants will pair well with it. For optimal growing conditions, plant basil in nutrient-rich, slightly acidic to neutral soil (6.0-7.5). Basil should be watered regularly and kept moist in well-draining soil with full sun, at least six to eight hours a day. Basil has shallow roots, making competition for nutrients and water tough if it’s planted next to a heavy feeder.
What Not To Grow With Basil
Here are some plants you shouldn't plant near your basil:
Sage
While basil likes consistently moist soil that’s rich in nutrients, sage (Salvia officinalis) doesn’t mind drier conditions. The drought-tolerant herb prefers less feeding. If grown together, neither of these plants may thrive, which may result in stunted growth. It’s best to plant them separately so each will flourish.
Cucumbers
While basil’s strong fragrance can deter garden pests like aphids and spider mites that can be harmful to cucumbers, that scent can affect the flavor of your cucumbers too, giving them a bitter or floral taste. Cucumbers also need plenty of water, which can cause the two plants to compete for moisture and nutrients.
Fennel
Fennel (Foeniculum vulgare) isn’t a good companion plant for most plants because it releases allelopathic compounds from its roots, which can stunt growth and harm the plants growing near it. Basil that isn’t growing well can be susceptible to pest and disease problems. Fennel also prefers slightly dry alkaline soil compared to the moist slightly acidic soil basil likes. These plants will compete for nutrients too.
Rue
Rue (Ruta graveolens) is another allelopathic plant that shouldn’t be grown next to basil. An evergreen herb, rue is commonly grown as an ornamental plant for its yellow flowers and as a host for swallowtail butterflies. It’s best grown away from the garden since, like fennel, it can stunt the growth of basil and other plants growing nearby.
Cabbage
Basil can be beneficial to cabbage (Brassica oleracea) because it deters harmful pests like cabbage worms and slugs, but the two plants can compete for water and sunlight. That can mean that neither plant will thrive. Cabbage also prefers to grow in cooler temperatures, about 60ºF to 65ºF. Basil likes it a bit warmer with temperatures between 75ºF and 85ºF.
Thyme
Basil and thyme (Thymus vulgaris) have different watering requirements. Basil likes frequent water and moist soil while thyme likes a drier environment. Planting these two herbs together will cause one of them to struggle since needs cannot be met for both plants.
Kale
Kale and basil won’t necessarily harm one another, but they have different growing requirements that make them incompatible. Basil grows in warm seasons in plenty of sunlight, while kale likes cooler temperatures below 75ºF. It can also take some shade. Growing these two plants together can be a challenge that’s not worth it.
What You Should Grow With Basil
There are many other options that make good companion plants for basil. Improve pollination by growing it near zinnias or chamomile, which attract pollinators. Marigolds and garlic will help keep pests away. Boost the flavor of your tomatoes by planting them near basil, or grow basil with herbs that have similar growing requirements, like parsley and oregano, in a culinary herb garden.
