We advise you to use the cold hardiness map as a guide and a guide only. It is at best a guesstimated production and may prove unreliable in your part of the country.
For instance the cold hardiness map is based on lets say about a quarter of a century of average low temperatures and that fact alone can lead to disappointment if too much creditability is placed upon the maps accuracy.
Should you be new to gardening or have moved to another state we suggest that you use the map as a starting point and then consult with a local experienced horticulturist as to how various plants have faired in relation to the cold map.
Also be sure to check out your first and last average frost dates for your location.