What plant hardiness zone is Helena Valley Northeast

Helena Valley Northeast is located at Lewis and Clark County, Montana (MT), USA.

Plant hardiness zone (winter frost zone or gardening zone) for Helena Valley Northeast is 4b by the USDA scale.

Coldest zone's winter temperature is −25 … -20 °F.

Plants of 4b USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 4b USDA.

Helena Valley Northeast, Montana @ wikipedia.