Dill (Anethum graveolens) is an aromatic herb known for its fine, feathery foliage and distinctive flavor. The practice of companion planting involves strategically placing different plant species near each other to create a synergistic environment that promotes growth, enhances flavor, or provides natural pest control. Dill is a powerful companion plant that can significantly influence the health and productivity of its neighbors, making its placement a thoughtful decision for gardeners.
Plants That Thrive Near Dill
Dill offers a protective benefit to several common garden vegetables, most notably members of the Brassica family, such as broccoli, cauliflower, Brussels sprouts, and cabbage. These plants are often plagued by pests like the cabbage worm and cabbage looper. Dill’s strong, characteristic scent helps to mask the odor of the Brassica plants, making them harder for these specific pests to locate and infest.
Dill’s presence near these cole crops can also result in enhanced growth and flavor. Lettuce is another plant that pairs well with dill because both prefer similar cool growing conditions and moist soil. Furthermore, dill can help deter certain insects that target the tender leaves of lettuce.
Corn is a surprising but effective companion for dill, as the tall stalks provide necessary support and shade. Dill’s blooming flowers attract beneficial insects that prey on corn pests. As dill grows to maturity, its umbrella-shaped flower heads become a natural insectary, drawing in predators that keep common corn pests like armyworms in check.
Plants to Avoid Planting Near Dill
Carrots are a primary example of a bad pairing because both plants belong to the same Apiaceae family, which can lead to shared pest problems. Planting them near each other can attract the carrot rust fly, which damages the carrot roots, with dill acting as an accidental beacon for the pest.
Tomatoes can also suffer if dill is left to fully mature and go to seed near them. Once dill begins to set seed, it can release compounds into the soil that inhibit the growth of nearby plants, reducing the yield of the tomato crop. If a gardener chooses to plant them together, the dill plants must be removed before they reach full maturity and begin to flower.
Fennel is perhaps the most problematic plant to place near dill or any other garden crop, as it is highly allelopathic, meaning it releases chemical substances that actively suppress the growth of almost all surrounding plants. While dill and fennel are related, planting them in proximity can result in cross-pollination, potentially creating a hybrid with a poor, bitter flavor profile. These incompatible relatives should be planted far apart or, ideally, fennel should be isolated in its own container.
How Dill Supports Garden Health
Dill’s contribution to garden health is rooted in its unique physical characteristics and aromatic properties. The herb’s characteristic strong scent, derived from its volatile oils, is effective at repelling certain harmful insects, like the cabbage looper, by disrupting their ability to find their host plants. This olfactory confusion is a major factor in its protective capacity for Brassicas.
The tall stems and delicate, umbrella-shaped flower clusters, known as umbels, are a magnet for beneficial insects. These flat-topped structures offer easy-access landing pads and a rich source of pollen and nectar for tiny natural predators. Specific insects attracted to dill include parasitic wasps, which lay their eggs inside garden pests like the tomato hornworm, and hoverflies, whose larvae are voracious predators of aphids.
Dill also attracts ladybugs and lacewings, which control populations of soft-bodied pests such as aphids and spider mites. By offering a reliable food source and shelter, dill encourages these natural enemies to establish a presence. Allowing a few dill plants to flower fully cultivates a self-sustaining ecosystem that reduces the need for external pest interventions.