Arugula, often known as rocket, is a popular leafy green vegetable prized for its signature peppery flavor. The question of whether it is a perennial is a common source of confusion among gardeners due to different species sold under the same name. The arugula found in grocery stores and seed packets is botanically classified as an annual, completing its life cycle within a single growing season. However, a different species, often called “wild arugula,” reliably acts as a true perennial, surviving for multiple seasons.
Arugula’s Botanical Classification
The widely cultivated variety, Garden Arugula (Eruca vesicaria), is formally categorized as an annual plant. An annual completes its entire cycle—germinating, growing, flowering, and dying—within one year. This species matures quickly, often ready for harvest within 40 to 50 days, and tends to “bolt,” or send up a flower stalk, as temperatures rise, signaling the end of its productive life.
A biennial plant requires two full growing seasons to complete its life cycle, typically flowering and setting seed in the second year. While Eruca vesicaria is strictly an annual, it can sometimes behave like a biennial in regions with extremely mild winters. In these conditions, the plant may survive the cold season and resume growth and flower the following spring, but it is not a true biennial.
A perennial plant lives for more than two years, growing and flowering repeatedly from the same root system. Most garden arugula lacks the robust root structure or hardiness to reliably survive multiple years. The common garden type is genetically programmed to die shortly after setting seed.
Factors Influencing Perennial-Like Behavior
The perception that garden arugula is a perennial usually stems from its enthusiastic tendency toward self-seeding, which creates “volunteer” plants. If the initial plant is allowed to flower and drop seeds into the soil, those seeds often germinate quickly into new plants. This behavior allows a patch of arugula to appear year after year without human intervention.
The seeds are small, produced in elongated silique pods, and disperse easily throughout the garden. Because the seeds germinate readily, even in cool soil, a gardener might mistake this new generation for the survival of the original plant.
Arugula’s tolerance for cold temperatures also contributes to confusion about its life cycle. While it bolts quickly in summer heat, the plant is relatively frost-tolerant and thrives in cool weather. In zones with mild winters, the plant can successfully overwinter, surviving light frost and producing leaves until the following year’s heat causes it to flower and die.
Comparing Garden Arugula and Wild Arugula
The confusion is resolved by recognizing that Wild Arugula (Diplotaxis tenuifolia) reliably displays perennial characteristics. This species is often sold as perennial wall-rocket or Sylvetta arugula. Unlike its annual cousin, Diplotaxis tenuifolia is structurally a short-lived perennial, capable of surviving for several years in many climates.
Wild Arugula has firm stem bases and a root system that allows it to regenerate new foliage after being cut back or surviving winter dormancy. Its leaves are typically more deeply lobed and narrower than Garden Arugula, and it produces small yellow flowers instead of white or pale yellow ones.
The flavor profile is also distinct, with Wild Arugula having a more intense, peppery, and pungent taste due to higher concentrations of glucosinolates. This robust nature and ability to grow back after harvesting makes it a preferred choice for gardeners seeking a long-term planting of arugula.