Why Smart Gardeners Are Planting Lovage Next To Their Tomatoes

Growing your own tomatoes can be an extremely rewarding experience, but it often comes with its own set of hurdles — namely, the creepy-crawly kind. Common pests like aphids and the dreaded tomato hornworms, the caterpillar form of a type of sphinx moth, can wreak havoc on otherwise healthy tomato plants. Left unchecked, one caterpillar can eat the leaves and fruit of an entire plant. Instead of pesticides, many gardeners turn to companion planting as one of the oldest and most natural forms of pest control. While some plants aid nearby fruits and vegetables by simply deterring harmful pests, lovage (Levisticum officinale) puts a creative spin on pest control by attracting beneficial insects that prey on aphids, tomato hornworms, and other devastating pests.

Lovage is an herbaceous perennial plant hardy in USDA Hardiness Zones 3 through 8, meaning this natural form of pest control will return to your garden each year. It grows well in full to part sun and requires a balanced, loamy, and slightly acidic soil, making it ideal to plant alongside tomato plants, which prefer similar conditions. But this fragrant herb has a hidden talent — its blooms, yellow-green clusters that form a small umbrella over the stalk, entice beneficial insects like parasitic wasps to the area. These natural predators are key to controlling nuisance pest populations. 

Beneficial insects are bugs that, instead of damaging plants, protect or aid plant health by banishing pests from your garden. Examples include predatory bugs like ladybugs, lacewings, and spiders. One of the largest categories of beneficial insects, however, is parasitic wasps. Unlike social wasp species, which include paper wasps and hornets, parasitic wasps are not likely to sting humans. In fact, many species are so tiny they're hardly noticeable. Their superpower, however, lies in their offspring.

As adults, parasitic wasps lay their eggs inside host creatures. When the eggs hatch, the wasp larvae feed off the host, which will eventually succumb to the parasites. Certain species, such as braconid wasps, are particularly effective against aphids and tomato hornworm. Often, the easiest way to remove these pests is to physically pluck them from the foliage. But these masters of disguise can easily blend in with your tomato plant, making them hard to spot until it's too late. By planting lovage as a companion plant in your garden, you can attract parasitic wasps to do the work for you, ensuring a bountiful season of pest-free tomatoes.