What plant hardiness zone is River John
River John is located at Pictou County, Nova Scotia (NS), Canada.
Plant hardiness zone (winter frost zone or gardening zone) for River John is 5b by the PHZ Canadian scale.
Plants of 5b PHZ hardiness zone suitable for outdoor gardening and growing in this winter frost zone 5b PHZ.
Also perennial plants from the equivalent USDA zone 4b with coldest winter temperature −31.7 … −28.9 °C and lower can be grown here, see list of plants for 4b USDA winter zone.
River John, Nova Scotia @ wikipedia.