Following last week’s leaf on breaking dormancy (https://lnkd.in/dznBEz7e), this week we spotlight another dramatic change in plant growth, bolting, when plants switch from leafy growth to flowering.

Take broccoli, for example. The cover photo shows it not as the familiar tight green head, but as a tall, flowering stalk. That’s bolting. It usually happens late in the season, but some plants wait till the following year before they bolt and bloom.

Broccoli, rapeseed, cabbage, turnip and other members of the cabbage (Brassicaceae) family all bolt, as doplants in many other botanical families. Gardeners will be familiar with bolting in lettuce (Asteraceae), beetroot (Amaranthaceous) and other vegetables. Bolting is also common in the carrot family (Apiaceae), including two species that Green Mountain Biotech uses to make bioactivecosmetic ingredients, Chinese Angelica (Dang gui, 当归) and Cnidium (Shechuangzi, 床子).

Carrots are “biennial”, growing vegetatively the first year and then bolting and flowering in year two, though sometimes environmental stress brings it on earlier. Gardeners will tell you that carrots harvested from bolted plants have a bitter flavour.

Cnidium, is an “annual” plant growing and flowering the same year. This is not only desirable but essential to produce the extractable fruit that yields Osthole and other bioactive molecules.

For Angelica the story is quite different. Typically a triennial plant, Angelica bolts and flower only in year three. According to Pan et al (2025) the phytochemical content is best in year two and declines in year three when bolting occurs. Therefore, the best bioactive extracts should be made from roots harvested in year two or early in year three before the plants bolt.

As Solomon wisely said, “To everything there is a season …a time to plant and a time to harvest” – Ecclesiastics3:1

Further reading

⚘Wikipedia (2025) “Bolting (horticulture)”, https://w.wiki/EkX3

⚘Wikipedia (2025) "Angelica sinensis”, https://w.wiki/EkYB

⚘Wikipedia (2025) “Cnidium monnieri”, https://w.wiki/EkY7

⚘PanX, Gu Z, Yang Y, Sa R., Wang Y (2025). Analysis of Angelica sinensis at different growth stages by 1H NMR-based metabolic fingerprinting combined with chemometrics. J Chromatogr B, 1263, 124676.https://doi.org/10.1016/J.JCHROMB.2025.124676

⚘Li M, Li M, Wang L, Li M, Wei J. (2023). Apiaceae Medicinal Plants: A Review of Traditional Uses, Phytochemistry, Bolting and Flowering, and Controlling Approaches. Molecules 28, 4384. https://doi.org/10.3390/molecules28114384

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