Arugula Bolting – What Causes It?

Arugula is a leafy green, commonly used in salads, with a peppery kick. As with most plants, naturally, arugula will flower and go to seed, ensuring its survival. In other plants like strawberries or peppers, this is a good sign of development and fruit inevitable. However, this is not desired in plants primarily harvested for their leaves, as the flowering process alters the crop’s taste. You will see this referred to as “arugula bolting,” though it is not necessarily a self-explanatory term. What is arugula bolting? 

Arugula bolting is the term used for when your arugula goes to flower, signifying it is past its prime and too bitter to eat raw. This is a normal part of the arugula life cycle, though it can be prevented long enough to ensure a good harvest of your arugula when it is at its peak flavor. 

Read on to figure out what causes bolting, what can be done with bolted arugula, and tips on how to stave off bolting. 

What causes arugula bolting? 

Arugula “bolting” is caused by your plant’s natural progression to go to flower and is an entirely normal process. The plant puts its energy into producing flowers, making the leaves much more bitter and unpleasant tasting. Usually, gardeners will want to avoid the flowering stage for as long as possible to get as many harvests of arugula with the pleasant pepperiness it is known for. 

Bolting cannot be controlled entirely; there are some things you can do to extend the life of your arugula before it goes to flower:

• Grow in cooler climates. A cool weather crop already, planting arugula during the fall will extend your harvest.
• Plant in shaded locations with adequate humidity. The shade will slow the plant’s growth while providing humidity still ensures your plant stays hydrated and healthy. 
• Pinch off flowers as you see them. This won’t prevent bitterness from developing in the leaves, but it will slightly extend the amount of time you have left before they become less desirable to eat.

These tricks can be used only for so long before your plant takes its course. Fortunately, with a short time to harvest, arugula can be planted in early springtime and during early fall before freezing temperatures set in. 

When should arugula be harvested? 

Arugula should be harvested regularly throughout its life to get the most out of your crop. If you’ve planted it from seed, this can be about a month after planting, though it can take up to 45 days to mature. 

Young arugula can be picked if your preference is a mild and tender flavor, and pick the leaves at about 2 to 3 inches in length. Wait for the leaves to grow larger and more robust for a stronger, peppery flavor. A mature leaf is between 6 to 8 inches long when they are at its peak; the larger the leaves get, the more tough and bitter they are in taste and texture. 

Harvesting arugula should be done frequently in small amounts, starting from the outside portions of your plant. Cutting near the base of the plant encourages more growth, though you don’t want to over-pick your plant. Try to leave at least half of your plant intact between harvests to keep your plant producing more leaves.

Picking your arugula or other leafy greens is best done in the morning or evening hours to prevent wilting immediately after being picked. Use a damp paper towel to wrap your leaves and place them in an open bag to store the arugula. Storing your arugula like this will help keep it crisp without wilting or dehydrating from the cool air in the refrigerator. 

Arugula can continue to be harvested after the first few flowers are formed and then pinched off, though this indicates that the leaves will soon become bitter and tough. When you begin to notice this, you will know your arugula is done for the season. 

Can arugula bolting be fixed? 

Flowering and going to seed is the natural inclination of any flowering plant, as this is how they survive and reproduce. So, this fact of life cannot be fixed. Certain measures can be taken to slow down the process, though it will eventually flower and get to the point where the leaves are no longer pleasantly spicy but are instead bitter. 

While bolted arugula cannot be fixed, there is a bright side to let it take its natural course after you’ve gotten a satisfactory harvest. 

Bolted arugula can still have use in both the garden and the kitchen. Allowing your arugula to go to seed can also lead to self-sowing in your garden, meaning you can have another arugula harvest. Flowers are also attractive to pollinators, which are always good to have in your garden and around crops. 

Post-flowering arugula leaves and their flowers can still be edible and enjoyable in small amounts added to salads. Delicate in appearance with a nutty, peppery kick, the flowers can also be added to salads as a decorative and flavorful touch. 

Prepare for your arugula to bolt when warmer temperatures start occurring regularly; you will want to harvest your plant as many times as you can before this happens to get the best flavor without excessive bitterness. 

Final Thoughts

While arugula bolting cannot be fixed and is an inevitable part of the arugula life cycle, not all hope is gone once you see flowers appear. 

Before bolting, the arugula harvest can be extended by taking a few precautions to stave off flower formation. Pinch off flowers to add another harvest or two in before the leaves get too bitter. Use the flowers for decorative plating or as an addition to a salad or sandwich. 

Harvest your arugula regularly during its growing season before letting it flower and go to seed, which can benefit the rest of your garden in the form of pollinator activity and a future arugula harvest.