What plant hardiness zone is High Ridge
High Ridge is located at Jefferson County, Missouri (MO), USA.
Plant hardiness zone (winter frost zone or gardening zone) for High Ridge is 6a by the USDA scale.
Coldest zone's winter temperature is −10 … -5 °F.
Plants of 6a USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 6a USDA.
High Ridge, Missouri @ wikipedia.