What plant hardiness zone is Heiden

Heiden is located at Vorderland, Appenzell Ausserrhoden (Outer-Rhodes) (AR), Switzerland.

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

Coldest zone's winter temperature is −23.3 … −20.6 °C.

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

Alternative climatic zone of gardening for Heiden by UK RHS scale is H7.

Plants of H7 RHS hardiness zone suitable for outdoor gardening and growing in this winter frost zone H7 RHS.

Heiden, Switzerland @ wikipedia.

* The lowest temperature in Heiden was -20.7 °C on 06/02/2012.