Cilantro / Coriander + Tomato

Cilantro and tomato are a practical pairing in the vegetable garden, with the benefit flowing primarily through pest suppression. Cilantro that is allowed to bolt produces small white flowers that attract parasitic wasps, which parasitize tomato hornworm eggs and reduce aphid populations. The effect is most pronounced when cilantro is flowering, so timing matters: stagger plantings so at least one cilantro plant is in bloom during the period when tomatoes are setting fruit.

Positioning requires some thought. Cilantro is a short, cool-season plant that bolts quickly in heat; tomatoes are tall and heat-loving. Plant cilantro to the north of tomato rows to avoid shade competition. In zones 7 and warmer, cilantro planted in early spring will often bolt by the time tomatoes are established, which is actually ideal for the flowering benefit. A second planting in late summer, after peak heat, can extend the bloom window into early fall.