Garden Club of Ohio Inc.
Zone 2 -50º to -40º  Zone 7 0º to 10º
Zone 3 -40º to -30º  Zone 8 10º to 20º
Zone 4 -30º to -20º  Zone 9 20º to 30º       
Zone 5 -20º to -10º  Zone 10 30º to 40º
Zone 6 -10º to -0º  

    The US Department of Agriculture Plant Hardiness Zone Map, revised in 1990, shows the lowest
    temperatures that can be expected each year in the United States. These temperatures are referred to as
    "average annual
    minimum temperatures" and are based on the lowest temperatures recorded for each of the years 1974
    to 1986. The different zones represent areas of winter hardiness for agricultural and natural landscape
    plants.

    For each plant we offer, we include a range of hardiness zones, for instance, Zones 3-8. This means that
    we think that as far as temperature goes, that a particular species when established should be able to
    grow
    anywhere on the map between and including Zones 3 to 8. This is very general and one would need to
    take into account specific cultural and habitat requirements. So use a zone to determine minimum
    temperature thresholds and our ranges to determine broad climate tolerances.
US Department of Agriculture Plant Hardiness Zone Map