Variety traits

Winter Hardiness of Agastache Clayt. ex Gronov.

Agastache Clayt. ex Gronov.

A critical trait determining the longevity of Agastache, depending on the cultivar's ability to withstand critical temperatures and the resistance of the root crown to crown rot under waterlogged conditions.

In the reference 8 varieties crop Giant hyssop, where this is mentioned in the description.

For the genus Agastache, winter hardiness is assessed primarily based on USDA hardiness zones in the 5–9 range, as well as actual field survival of the root system and the ability to regrow in spring. Species affiliation determines the resistance potential: species such as Agastache rugosa are better adapted to cold and wet winters, while Mexican and southwestern North American species are sensitive to winter precipitation.

A key threat to the plants is 'winter dampness', where mortality occurs due to excessive moisture and decay of the root crown rather than solely from low-temperature exposure. In regions with unfavorable overwintering conditions, the crop is grown as an annual, or agronomic measures are employed: avoiding autumn stem pruning, installing drainage in plots, and using dry cover.

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

Sources8

Varieties of Giant hyssop 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.