Bolting is the production of a flowering stem (or stems) on agricultural and horticultural

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponic ...

s before the crop is harvested, in a natural attempt to produce seeds and

reproduce Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual org ...

. These flowering stems are usually vigorous extensions of existing leaf-bearing stems, and to produce them, a plant diverts resources from producing the edible parts such as leaves or roots, resulting in flavor and texture changes, withering, and in general, a poor quality harvest. Plants that have produced flowering stems in this way are said to have bolted. Crops inclined to bolt include

lettuce Lettuce (''Lactuca sativa'') is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, ...

basil Basil (, ; ''Ocimum basilicum'' , also called great basil, is a culinary herb of the family Lamiaceae (mints). It is a tender plant, and is used in cuisines worldwide. In Western cuisine, the generic term "basil" refers to the variety also kno ...

beetroot The beetroot is the taproot portion of a beet plant, usually known in North America as beets while the vegetable is referred to as beetroot in British English, and also known as the table beet, garden beet, red beet, dinner beet or golden beet ...

brassicas ''Brassica'' () is a genus of plants in the cabbage and mustard family (Brassicaceae). The members of the genus are informally known as cruciferous vegetables, cabbages, or mustard plants. Crops from this genus are sometimes called ''cole cro ...

spinach Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either f ...

celery Celery (''Apium graveolens'') is a marshland plant in the family Apiaceae that has been cultivated as a vegetable since antiquity. Celery has a long fibrous stalk tapering into leaves. Depending on location and cultivar, either its stalks, lea ...

onion An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion ...

, and

leek The leek is a vegetable, a cultivar of ''Allium ampeloprasum'', the broadleaf wild leek ( syn. ''Allium porrum''). The edible part of the plant is a bundle of leaf sheaths that is sometimes erroneously called a stem or stalk. The genus ''Alli ...

. Bolting is induced by plant hormones of the

gibberellin Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. GAs are one of the longest-known classes of p ...

family, and can occur as a result of several factors, including changes in day length, the prevalence of high temperatures at particular stages in a plant's growth cycle, and the existence of stresses such as insufficient water or minerals. These factors may interact in a complex way. Day length may affect the propensity to bolt in that some plants are "long day plants", some are "short day plants" and some are "day neutral" (see

photoperiodism Photoperiodism is the physiological reaction of organisms to the length of night or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light a ...

), so for example when a long day plant, such as spinach, experiences increasingly long days that reach a particular length, it will be inclined to bolt. Low or high temperatures can affect the propensity of some plants to bolt if they are experienced for sufficient periods at particular points in the life cycle of the plant; once these conditions have been met, plants that require such a trigger will subsequently bolt regardless of subsequent temperatures. Plants under stress may respond by bolting so that they can produce seeds before they die. Plant breeders have introduced

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

s of "bolt-proof" crops that are less prone to the condition.

References

{{Reflist Horticulture