What plant hardiness zone is Riddes

Riddes is located at Martigny, Valais (Wallis) (VS), Switzerland.

Plant hardiness zone (winter frost zone or gardening zone) for Riddes 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 Riddes 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.

Riddes @ wikipedia.

* The lowest temperature in Riddes was -20.6 °C on 27/02/2018.