Arugula (Eruca vesicaria), often called rocket, is a popular, fast-growing leafy green known for its peppery flavor. For gardeners, this plant possesses a “cut-and-come-again” trait, meaning it grows back after being harvested. This allows for multiple harvests from a single planting, providing a continuous supply of fresh leaves over a sustained period.
Arugula’s Growth Habit and Regrowth Mechanism
Arugula’s regrowth capability stems from its rosette habit. The plant produces a cluster of leaves that radiate outward from a central point at the soil line, known as the basal growth point or crown. This central growing tip contains the plant’s meristematic tissue, which is responsible for cell division and the production of new leaves.
When the outer leaves are removed, the plant does not regrow from the cut tissue. Instead, the established root system and its stored energy reserves divert resources to the intact crown. This stored energy enables the meristem to continuously push out fresh, tender leaves from the center of the rosette. This mechanism allows the plant to sustain itself by ensuring enough photosynthetic surface remains to gather light and create the energy needed for subsequent growth cycles.
Maximizing Harvests Through Proper Cutting Techniques
To ensure a sustained and robust yield, harvesting arugula requires a specific technique that protects the plant’s growth mechanism. The most effective method is to harvest the oldest, most mature leaves from the outside of the plant first. Their removal signals the plant to focus its energy inward on new development.
When cutting, use clean scissors or snips and sever the leaf stem close to the ground, but be careful not to damage the central crown. You must leave the small, emerging leaves in the center untouched so the plant can continue its growth cycle.
To maintain plant health and encourage rapid recovery, never remove more than one-third of the total foliage from a single plant at one time. Removing too much stresses the plant, reducing its ability to photosynthesize and slowing the rate of regrowth.
Regularly harvesting the larger leaves also reduces the overall bitterness, as smaller, younger leaves tend to have a milder flavor. By preserving the central growing point, the harvest window can be extended.
The End of Regrowth: Understanding Bolting
The period of continuous regrowth is ultimately limited by the plant’s natural life cycle, which concludes with bolting. Bolting occurs when the arugula plant shifts its energy from producing edible leaves to developing a tall, rigid flower stalk for reproduction and seed production. This transition is primarily triggered by environmental factors, including rising ambient temperatures and increasing daylight hours.
Once bolting begins, the plant’s hormones direct resources toward the reproductive structures, causing a rapid decline in new leaf growth. The existing leaves often become smaller, tougher, and take on a more deeply lobed, serrated shape. A noticeable consequence of this process is a significant increase in the concentration of compounds that cause a sharp, bitter flavor.
Though the leaves become less palatable after bolting, the plant remains useful. The flowers that develop on the stalk are edible and possess a mild peppery taste. Allowing the plant to fully mature and set seed can provide seed for future plantings or attract beneficial pollinators. However, for the purpose of salad greens, bolting marks the natural conclusion of the plant’s productive regrowth phase.