Variety traits

Winter Hardiness — Buddleja davidii

Buddleja davidii Franch.

The winter hardiness of Buddleja davidii is evaluated using USDA hardiness zones 5–9 and its ability to annually regenerate its above-ground parts from the root system following winterkill.

In the reference 21 varieties crop Butterfly bush, where this is mentioned in the description.

The winter hardiness of Buddleja davidii is determined by the plant's ability to regenerate current-season shoots, upon which inflorescences are formed. In USDA zones 5–6, the above-ground portion often dies back at temperatures below -15...-25 °C; however, the root system remains viable and ensures vigorous growth in the spring.

From an agrotechnical perspective, this trait is directly linked to pruning strategy: where there is a risk of wood freezing, severe pruning of the shrub is practiced, which stimulates flowering on new shoots. Beyond temperature minima, the crop's winter hardiness is critically dependent on soil drainage, as waterlogging of the roots during the winter period increases the risk of plant mortality.

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

Sources8

Varieties of Butterfly bush 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.