Arugula, also known as rocket, is a fast-growing leafy green prized for its distinct peppery flavor. Trimming the plant manipulates its natural growth cycle, ensuring a continuous supply of fresh, tender leaves throughout the season. Removing foliage encourages the plant to invest energy into new vegetative growth rather than seed production. This practice significantly extends the harvest period.
Knowing When to Begin Harvesting
The timing of the initial trim depends on the plant’s maturity and the desired size of the leaves. For the mildest flavor, the first harvest can begin approximately 20 to 25 days after sowing. At this stage, the young leaves are considered “baby greens” and measure about two to three inches in length.
Allowing the plant to reach 35 to 45 days after planting yields mature leaves that are four to six inches long. These larger leaves possess a more pronounced peppery flavor. Harvesting too early, before the plant has developed a healthy root system and sufficient foliage, can stress the young arugula and stunt production.
Proper Cutting Methods
The most effective approach for a sustained harvest is the “cut-and-come-again” method, which focuses on selective trimming. This technique involves using clean scissors or sharp snips to remove the larger, outer leaves. Cut the leaves near the base of the stem, being careful to avoid damaging the central growing point, known as the crown.
The crown is where new leaves continuously emerge, and keeping it intact is fundamental for regrowth. Never remove more than one-third of the plant’s total foliage at any given time. Removing too many leaves inhibits the plant’s ability to photosynthesize and recover quickly for the next harvest.
An alternative is the “shear” method, used for a rapid bulk harvest. When employing this technique, cut all the leaves to about one to two inches above the soil line. This extreme trimming can stimulate a new, albeit smaller, flush of growth, especially if the weather remains cool and the plant has not yet initiated its reproductive cycle.
Trimming to Prevent Bolting and Maintain Flavor
Arugula is a cool-season crop. When exposed to high temperatures, typically above 70°F, it undergoes bolting. Bolting is the plant’s natural response to stress, shifting energy from leaf production to quickly sending up a tall, central flower stalk to produce seeds. This physiological change causes the leaves to accumulate compounds that result in a bitter, unpalatable taste.
Aggressive, regular trimming is the most effective way to delay this progression. Frequently harvesting the mature outer leaves continually redirects the plant’s focus toward vegetative growth rather than reproduction. Inspect plants vigilantly for the emergence of a thicker, central stem that begins to grow taller than the rest of the foliage.
Upon identifying this central flowering stalk, immediately snip it off at the base to halt the bolting process. While this action may only temporarily delay bolting, especially in warm weather, it maintains the desirable mild, peppery flavor for a longer duration. Consistent soil moisture also reduces heat stress, working with trimming to prolong the season of tender leaves.