What plant hardiness zone is Trogen

Trogen is located at Mittelland, Appenzell Ausserrhoden (Outer-Rhodes) (AR), Switzerland.

Plant hardiness zone (winter frost zone or gardening zone) for Trogen is 6b by the USDA scale.

Coldest zone's winter temperature is −20.6 … −17.8 °C.

Plants of 6b USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 6b USDA.

Alternative climatic zone of gardening for Trogen by UK RHS scale is H6.

Plants of H6 RHS hardiness zone suitable for outdoor gardening and growing in this winter frost zone H6 RHS.

Trogen AR @ wikipedia.

* The lowest temperature in Trogen was -20.6 °C on 06/02/2012.