Allblossom
ActiveHypericum L. · St. John's wort
ALLPLANTS HOLDING B.V.|STUART SCOTT
Variety traits
Frost resistance of St. John's wort
Hypericum L.
The ability of St. John's wort to withstand sub-zero temperatures, measured by the LT50 index, which varies from -4 °C to -11 °C and lower depending on the species. This trait determines the longevity of perennial stands and the potential for introducing various forms into different climatic zones.
In the reference 4 varieties crop St. John's wort, where this is mentioned in the description.
To assess the frost resistance of St. John's wort species, the LT50 index is used, reflecting the temperature at which 50% of tissues die or are damaged. Studies demonstrate a wide range of resistance: from -4 °C in thermophilic species to values below -11 °C in species adapted to temperate climates. For example, Hypericum perforatum possesses pronounced natural winter hardiness, allowing it to grow without additional protection.
In commercial cultivation, frost resistance is a key factor determining the productivity and survival of perennial plantations. Low temperatures act as a stressor that not only affects plant density but also impacts metabolism, altering the intensity of the biosynthesis of pharmacologically significant compounds, such as naphthodianthrones and phloroglucinols.
General information about the subject — on the page Frost hardiness.
Varieties of St. John's wort mentioned in the description
Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.
Methyra
ActiveHypericum L. · St. John's wort
Marc Etienne