Last Update 02/15/09

Plant Hardiness Zones

About Plant Hardiness Zones

Plant hardiness zones are a general guide to help you know which plants will grow where you live because plants vary in the temperature extremes they can endure.

Years ago botanists and horticulturists started gathering weather records throughout the United States to build a database to show the average coldest temperatures for each region of the U.S.  These records were consolidated into a range of temperatures and converted into various zones of plant hardiness. Maps were then made to show the delineations between these temperature zones.

Arbor Day Foundation Hardiness Zone Map

 

The USDA map (can be viewed below for Florida), was last updated and released in 1990 (based on weather records from 1974-1986) and was the standard measure of plant hardiness throughout the United States until 2006. In 2006 the Arbor Day Foundation completed an extensive updating of U.S. Hardiness Zones based upon data from 5,000 National Climatic Data Center cooperative stations across the continental United States.

 

Please be aware that Plant Hardiness Zones are only a general guide.  Many other factors influence whether a plant will survive in your garden or not. You must also consider: Soil types, rainfall, daytime temperatures, day length, wind, humidity and heat. Within your own yard, block and county, there are microclimates that affect how plants grow.  One part of your yard may be hotter, colder, wetter, dryer, shadier or sunnier than another and certain plants may do better in one spot than another because of this. The zones are a good beginning, but you still need to determine for yourself what will and won't work in your garden.

The FloridaGardener Interactive Web Version of the 1990 USDA Plant Hardiness Zone Map for Florida.

Compare the color of the section in your area on the map with the color key below. Click on the general area of where you live for a closer look.

Florida Hardiness Zones