Herb Companion Planting — Which Herbs Grow Well Together

Companion planting uses the natural properties of plants — their scent, root chemistry, and pest-repelling compounds — to benefit their neighbours. Herbs are some of the most useful companion plants in the garden, attracting beneficial insects, deterring pests, and improving the flavour of some vegetables when grown nearby. But some herbs are better kept apart, either because they compete for the same resources or because of allelopathic effects.

Classic Beneficial Pairings

Basil and tomatoes is perhaps the most famous herb companion pairing — growing basil between tomato plants is widely believed to improve tomato flavour and deter aphids and whitefly. The aromatic oils in basil do appear to confuse pests, and the combination is beneficial in a practical sense even if the flavour enhancement is debated scientifically. Dill and parsley attract hoverflies and parasitic wasps that prey on aphids — plant them near roses, brassicas, and vegetables that suffer from aphid attacks. Chives planted near carrots may help reduce carrot fly damage by masking the carrot scent.

Herbs That Attract Pollinators and Beneficial Insects

Allowing some herbs to flower is one of the most beneficial things you can do for a productive kitchen garden. Flowering thyme, oregano, borage, and dill are magnets for hoverflies, bees, and parasitic wasps — all of which increase pollination and natural pest control. Plant these near your fruit and vegetable crops rather than in an isolated herb bed. Borage in particular is an exceptional pollinator plant that self-seeds readily and can be positioned near strawberries and squash for noticeably improved fruit set.

Herbs That Repel Pests

Several herbs produce aromatic compounds that deter specific pests. Rosemary planted near brassicas may help deter cabbage white butterflies. Mint (kept in containers to prevent spreading) near brassicas and alliums may reduce aphid and flea beetle pressure. Lavender planted near roses deters aphids and attracts pest predators. These effects are real but not absolute — companion herbs support, rather than replace, other pest management practices.

Incompatible Combinations to Avoid

Some herbs inhibit the growth of nearby plants and should be kept away from sensitive crops. Fennel is the most significant — it suppresses tomatoes, peppers, brassicas, and many other vegetables and should be positioned well away from the kitchen garden or grown in a container. Sage and onions are reportedly poor companions, as are dill and carrots when both are mature (though young dill with carrots is reportedly beneficial). Within the herb family, avoid planting dill near fennel as they can cross-pollinate.

Mediterranean Herbs Together — A Natural Match

Grouping Mediterranean herbs together is both practically and aesthetically sound. Rosemary, thyme, oregano, sage, and marjoram all prefer the same conditions: full sun, well-drained soil, limited watering, and minimal feeding. Planting them together means a single watering and care regime suits all of them. Their aromatic foliage also creates a fragrant border that deters a range of common garden pests and provides year-round structure in the garden.