Bolting (horticulture)

Bolting is the growth of an elongated stalk with flowers grown from within the main stem of a plant. This condition occurs in plants that are grown for their leaves, such as cabbage, lettuce, spinach, and other leafy greens.

Bolting can also apply to some of the brassicas that are grown for their flowers (such as broccoli and cauliflower) that send up flowering stalks too early, producing heads that are smaller than desired because the plant has not matured sufficiently to create a good sized crop.

Bolting normally appears in hot weather and is an attempt by the plant to procreate as the elongated stalk contains flowers which are full of pollen and/or seeds. Bolting is usually caused by the plant being exposed to extremely cold temperatures early in its life, although the condition will not manifest itself until air temperature increases. Because it gives the plant a bitter taste, bolting is considered undesirable by commercial growers although there are people who prefer the bitter taste provided by the process.