Variety traits

Agapanthus cold hardiness

Agapanthus L'Hér.

A critical parameter determining the feasibility of open-field cultivation through the assessment of USDA zones and the LT50 index. It includes the physiological vulnerability of rhizomes to temperatures below –3.9°C.

In the reference 10 varieties crop Lily of the Nile, where this is mentioned in the description.

Agapanthus cold hardiness is characterized by a narrow physiological range due to a low content of cryoprotective sugars and proteins in the fleshy rhizomes. A decrease in soil temperature below –3.9°C for more than 48 hours triggers the formation of intracellular ice, causing tissue rupture and the death of the growth point.

In scientific practice, cold tolerance is measured by the LT50 index, which determines the threshold of death for 50% of samples under experimental cooling. In breeding and agronomy, it is standard to divide forms into evergreen types, which overwinter in zones 9–11, and more hardy deciduous hybrids capable of tolerating conditions in zones 6–7, provided there is additional mulching or protection.

General information about the subject — on the page Frost hardiness.

Sources8

Varieties of Lily of the Nile 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.