Arugula is a quick-growing leafy green that adds a distinct peppery flavor to salads and sandwiches. As a cool-weather crop, successful cultivation depends entirely on timing the planting to avoid summer heat stress. Gardeners in Zone 7 must adhere to a precise schedule to manage this delicate balance of temperature and light. Understanding the climate parameters of your growing zone is the first step toward a successful harvest.
The Zone 7 Climate Context
The USDA Hardiness Zone 7 designation indicates an area where the average annual minimum winter temperature falls between 0°F and 10°F. The timing for annual vegetables like arugula is governed by the average frost dates. The typical last spring frost in Zone 7 falls between late March and early April, specifically March 22 to April 3.
Arugula thrives in the range of 50°F to 65°F, which characterizes the weather of early spring and late autumn. Seeds are cold-tolerant and can germinate in soil temperatures as low as 40°F. The average first fall frost date occurs much later, typically between late October and mid-November.
Spring and Fall Planting Windows
Spring Planting
The spring planting window is short and requires precision to maximize the yield before the heat arrives. Begin direct sowing seeds outdoors four to six weeks before the average last spring frost date. This early start allows the plant to mature during the cool period it prefers.
For a continuous supply, stagger planting by sowing new seeds every two to three weeks. Continue this succession planting until daily high temperatures consistently approach 70°F. Once the weather warms beyond this point, the spring harvest window typically closes.
Fall Planting
The fall season offers a significantly longer and often more successful period for growing arugula. Begin planting in late summer, timing your first sowing six to eight weeks before the average first fall frost date. This typically means starting your fall crop in late August or early September.
The gradually cooling temperatures and shorter days of autumn encourage vegetative growth rather than seed production. You can continue successive plantings until four to six weeks before the anticipated frost. Utilizing simple protection, such as row covers or a cold frame, can extend the fall harvest well into the winter months.
Preventing Premature Bolting
Arugula’s primary challenge is premature bolting, which is the plant’s shift from producing edible leaves to forming a flower stalk and seeds. This process is triggered by environmental stress, most often heat or irregular watering. Once a plant bolts, its flavor profile degrades and its leaf production slows significantly.
One effective strategy to delay bolting is to provide afternoon shade as temperatures rise above 70°F. This can be achieved by planting arugula on the east side of taller crops or structures that cast shadows, or by installing a shade cloth. This protection reduces the plant’s overall heat exposure during the hottest part of the day.
Consistent moisture is necessary to keep the plant cool and prevent stress. Arugula requires soil that is kept evenly moist, particularly during warmer spells. Allowing the soil to dry out between waterings can rapidly accelerate the bolting process.
Harvesting for Continuous Yield
The method used for harvesting directly affects how long your arugula patch remains productive. The most effective technique is the “cut and come again” method, which promotes continuous leaf production. This involves harvesting only the outer leaves of the plant, leaving the central growing point intact.
The ideal time to begin harvesting is when the leaves reach about two to three inches in length, roughly 30 to 40 days after sowing. By snipping the outer leaves, you allow the inner leaves to continue developing, extending the harvest for several weeks.
Alternatively, you may choose to cut the entire plant a half-inch above the soil line. If the temperatures remain cool, the plant may regrow for a second, smaller harvest. To ensure the best flavor, harvest all leaves before the plant shows any sign of developing a flower stalk.