Companion planting is a gardening practice that involves thoughtfully placing plants together so they can live symbiotically and work together to improve growth, deter pests, enhance flavor, and optimize soil health. Many herbs have natural pest-repellent properties through compounds that they create to deter pests and defend themselves, but these compounds are often also the compounds that create medicinal actions from these herbs. These herbs can be planted for medicinal use and harvest all while enhancing the well-being of neighboring plants. This short guide delves into the benefits of companion planting with some common medicinal herbs.
Why Companion Planting with Herbs?
Natural Pest Control
Certain herbs emit strong aromas (volatile oils) that the plant creates to deter pests. For example, basil repels aphids and whiteflies, while lavender keeps moths and mosquitoes at bay. These are incredible abilities plants have worked hard to evolve over millennia and contribute greatly to these plant’s survival. We can bring these incredible abilities into our gardens to deter pests without the use of pesticides.
Growth Enhancement
Some herbs release beneficial compounds that enhance the growth of their companions. Chamomile, for example, boosts the essential oil production of nearby herbs, making them more aromatic and potent. As the volitile oils are what we are seeking most in many of these medicinal herbs, interspersing chamomile is a great idea for maximizing medicinal constituents.
Attracting Pollinators and Beneficial Insects
Flowering herbs like calendula, echinacea, and borage attract bees, butterflies, and predatory insects such as ladybugs and lacewings, which help keep pest populations in check AND bring in valuable pollinators.
Soil Improvement
Certain herbs, such as clover and fenugreek, fix nitrogen in the soil, enriching it for surrounding plants. Others, like deep-rooted comfrey, draw up nutrients from the subsoil, making them available to nearby shallow-rooted plants and can be used to compost and re-distribute nutrients from one area of soil into your growing area.
Disease Prevention
Planting a diverse mix of herbs and companion plants reduces the likelihood of soil-borne diseases and discourages the spread of plant-specific pathogens. The more monocropping and segregation of plants the more likely your plants are to be targeted and overcome by soil-born diseases.
Best Herbal Companion Planting Pairings
Basil (Ocimum basilicum)
Best Companions: Tomatoes, peppers, oregano, chamomile, borage
Benefits: Repels mosquitoes, aphids, and whiteflies; enhances tomato flavor.
Avoid: Rue, sage, and common fennel.
Chamomile (Matricaria chamomilla)
Best Companions: Basil, mint, cabbage family plants, cucumbers
Benefits: Improves the health and essential oil production of nearby herbs; attracts beneficial insects.
Avoid: None known.
Calendula (Calendula officinalis)
Best Companions: Tomatoes, carrots, lettuce, cucumbers
Benefits: Repels nematodes and aphids; attracts pollinators and beneficial insects.
Avoid: n/a (A friend to alllll)
Cilantro (Coriandrum sativum)
Best Companions: Basil, tomatoes, spinach, anise, dill
Benefits: Repels aphids, spider mites, and attracts predatory insects.
Avoid: Fennel (they compete for resources).
Dill (Anethum graveolens)
Best Companions: Cabbage family, cucumbers, lettuce, onions
Benefits: Attracts parasitic wasps and ladybugs; improves cabbage plant growth.
Avoid: Carrots (stunts their growth).
Echinacea (Echinacea spp.)
Best Companions: Lavender, bee balm, calendula, thyme
Benefits: Attracts pollinators and boosts immune resilience in the garden.
Avoid: n/a
Lavender (Lavandula spp.)
Best Companions: Rosemary, thyme, sage, echinacea
Benefits: Repels moths, fleas, and mosquitoes; deters deer and rabbits.
Avoid: Moisture-loving herbs like basil and cilantro (lavender prefers dry conditions).
Lemon Balm (Melissa officinalis)
Best Companions: Basil, chamomile, tomatoes
Benefits: Repels mosquitoes and aphids; improves the flavor of nearby herbs.
Avoid: Mint (both are aggressive spreaders).
Mint (Mentha spp.)
Best Companions: Cabbage family, carrots, peas, tomatoes
Benefits: Repels cabbage moths, aphids, and flea beetles; improves soil moisture retention.
Avoid: Keep mint contained (it spreads aggressively and can overtake other plants).
Rosemary (Rosmarinus officinalis)
Best Companions: Sage, thyme, beans, carrots
Benefits: Repels carrot flies, cabbage moths, and slugs; deters deer.
Avoid: Basil (rosemary prefers drier soil).
Sage (Salvia officinalis)
Best Companions: Rosemary, cabbage family, carrots, strawberries
Benefits: Repels cabbage moths, slugs, and snails; improves flavor in neighboring herbs.
Avoid: Basil (needs more moisture).
Thyme (Thymus vulgaris)
Best Companions: Cabbage family, rosemary, strawberries
Benefits: Repels cabbage worms and whiteflies; improves flavor of vegetables.
Avoid: n/a
Herbs to Keep Separate
While most herbs thrive in diverse plant communities, some should be kept apart due to competition or growth inhibition:
Fennel – Produces compounds that inhibit the growth of most herbs and vegetables. Best grown alone.
Rue & Basil – Rue stunts basil’s growth.
Dill & Carrots – Can cross-pollinate or stunt each other’s growth.
Mint & Most Herbs – Mint spreads aggressively and can overtake neighboring plants. Keep it contained.
Spacing Tips:
Layering for Growth: Use taller herbs like dill and rosemary to provide partial shade to delicate herbs like cilantro and basil.
Spacing Matters: Some herbs (like mint and oregano) spread aggressively and should be contained in pots or separate beds.
Encourage Pollination: Let some herbs, like cilantro and basil, flower to attract bees and beneficial insects. This will attract beautiful insects and keep your garden abundantly polinated.
Interplant with Vegetables: Herbs like thyme, rosemary, and basil can be interspersed with vegetable plants to enhance flavor and deter pests naturally.
Incorporating companion planting techniques creates a healthy, resilient herb garden that thrives with minimal intervention. Think about the diversity of plants that grow in a wild meadow – we want to be as close to that as we can for optimal resilience. Understanding plant relationships helps us understand the deep complex relationships these beautiful beings have with each other and yes maximizes the yields we receive, but also gets us in closer relationship with the plants we have relied on for eternity.