How to Grow Dill

Dill flowers attract parasitic wasps — particularly Cotesia glomerata and Trichogramma species — whose larvae parasitise cabbage white caterpillars and imported cabbageworm eggs directly on the brassica leaves. Allow dill to reach full flower before the main caterpillar season for maximum wasp recruitment.

Dill's umbel flowers are rich in nectar and pollen that attract a broad range of beneficial insects including hoverflies, lacewings, and parasitic wasps that prey on aphids and cucumber beetles common on cucurbits. Sow dill in small successive batches alongside cucumbers so flowers are continuously available through the season.

Dill and fennel are both Apiaceae and share the same family of beneficial insect attractors — their umbel flowers draw the same parasitic wasps and hoverflies, compounding the effect in a mixed planting. Note that they can cross-pollinate when both are in flower simultaneously, producing off-type seeds if you're saving seed from either.

Dill's open umbel flowers provide a reliable nectar source for parasitic wasps and predatory beetles that help control the sweet potato weevil (Cylas formicarius) and whitefly populations that commonly affect sweet potato foliage. Plant dill at the bed perimeter where it won't compete with sweet potato's spreading vines for ground space.

Dill and carrot are both Apiaceae and can cross-pollinate freely when flowering simultaneously, producing hybrid seeds with unpredictable root shape and flavour. If growing for seed, stagger planting times to prevent overlapping flower periods, or keep them at least 100 m apart — though for eating crops only, brief proximity is generally fine.