Variety traits

Winter Hardiness of Clematis

Clematis L.

The ability of clematis to withstand winter temperatures, assessed using the USDA hardiness zone scale and a seven-point method, directly depends on the variety's pruning group.

In the reference 61 varieties crop Clematis, where this is mentioned in the description.

To evaluate the winter hardiness of clematis, USDA hardiness zones and the seven-point I. V. Vereshchagina scale are used, which allows for the quantitative determination of the degree of plant damage after overwintering. The level of resistance is closely related to the culture's classification into pruning groups.

Varieties in the third pruning group, such as Viticella, Integrifolia, and Jackmanii, possess high winter hardiness, withstanding temperatures down to -30...-35°C due to the annual renewal of shoots. Varieties in the first and second groups have low winter hardiness, are sensitive to temperatures below -20...-30°C, and require the preservation of previous year's shoots to ensure flowering.

When selecting varieties, the plants' reaction to sharp temperature fluctuations and thaws, which can cause premature sap flow, is taken into account. For less winter-hardy forms, it is critically important to organize protection against icing, excessive humidity, and damping off under cover.

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

Sources8

Varieties of Clematis 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.