How to Harvest Arugula
Harvest arugula when the leaves are big enough to eat. Harvest leaves one at a time or cut the entire head at once.
Arugula is a fast-growing cool-season salad green. It is ready for harvest 30 to 40 days after sowing.
Arugula leaves are tangy and peppery with a mustard-like flavor. Young leaves 2 to 3 inches long (5-7 cm) are mild; older leaves can be sharp flavored.
Arugula grows best between 60° and 65°F (15°-18°C)—commonly during spring or autumn. Plants will flower (bolt) and stop producing when temperatures reach the high 70°sF (21°+C) for several days in a row. If temperatures rise into the 80°sF (26°+C), start picking outer leaves immediately; this will briefly delay bolting.
More tips at How to Grow Arugula.
Leaves cut from plants that have produced flowers will be bitter and tough but still edible. Arugula flowers are also edible.
In mild-winter regions, arugula will often produce through the winter. In cold-winter regions, grow arugula under a plastic tunnel or in a cold frame. In a cold frame, you can keep arugula from freezing by covering plants with straw or hay. Overwintered arugula will give you an early spring harvest.
Harvest baby leaves or leaves to 8 inches (20 cm) long cut-and-come-again or cut the whole bunching head.
Cut arugula with a garden scissors or serrated bread knife. Leave one inch (2.5 cm) of individual leaves or an inch of the crown if you harvest the plant whole. Either way, the plant will keep producing new leaves as long as temperatures are cool.
Store arugula cold and moist, 32°-40°F (0°-5°C) and 95 percent relative humidity. Wrap leaves in a cloth or paper towel and place them in a perforated plastic bag in the vegetable crisper section of the refrigerator. Arugula will keep in the refrigerator for about 10 days but it will be most flavorful in used in 3 to 6 days.
Arugula leaves that are stored too cold or too long will develop wilt, yellow, and develop brown spots.