What plant hardiness zone is Castle Point

Castle Point is located at Saint Louis County, Missouri (MO), USA.

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

Coldest zone's winter temperature is −5 … 0 °F.

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

Castle Point, Missouri @ wikipedia.