About Plant Hardiness
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.
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.
FloridaGardener Interactive Web Version of
the 1990 USDA Plant Hardiness Zone Map
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.