The USDA Plant Hardiness Map is a good tool to use when deciding what plants will grow well in your region. If you don't already know your Zone, check out the links below for the Zone Map to your part of the country. As this is a U.S. government agency, they didn't think to include other countries, but our Canadian visitors can simply use the temperature guides below (or on the maps) to find out your USDA Zone equivalent for your area. You may have to consult with your local weather records to be sure.

Hardiness zones are sometimes referred to in gardening books, magazines as well as in mail order catalogs and nurseries. The GreenWeb sometimes references this information and is in the process of updating it's seed listings with the information whenever available.

It's important to remember that Zone information is a guideline. Within any region there are different climates due to various factors, like topography, water masses, canyon and mountain landmarks. These can cause airflows to be altered locally which can be enough to raise or lower your lowest temperature, thus possibly changing the appropriate Zone for your garden.

For plants that will grow inside your home, Hardiness Zones become far less important. Unless your prone to forgetting to pay the heating bill, it's doubtful the temperature will ever drop below Zone 11 (40 degrees Fahrenheit / 4.4 degrees Celsius). So, for all intensive purposes, you can consider your houseplant environment like Hawaii ! Many tub and container plants can take advantage of your home by being moved inside when the weather chills, and then back outside after the last frost has hit. Sort of a tropical winter-long vacation for your plants. Since plants also add to the home environment as well as freshening, cleaning and oxygenating the air, it's also a pleasant way for you to spend the winter as well. Especially considering that winter weather may force you to spend more time indoors.

Here are the links that will take you to the right Zone Map for your region. Be patient as they may take a few moments to load. For additional and detailed information about your Zone, look on this page past the map links that follow.

USDA ZONE MAP for Alaska & Hawaii, USA

USDA ZONE MAP for the Eastern Half of the USA Mainland

USDA ZONE MAP for the Western Half of the USA Mainland

Additional and Detailed USDA Hardiness Zone Info!

Below are specific details about what comprises your USDA Plant Hardiness Zone (or foreign equivalent) including the Celsius temperatures too. You'll also find some official USDA definitions and projected frost dates as well.

Approximate range of Average  
        Annual MINIMUM Temperatures

           C = Centigrade/  F = Fahrenheit

     Zone  1 =  below -45C/      -50F
     Zone  2 = -45C/-40C    -50F/-40F
     Zone  3 = -40C/-34C    -40F/-30F
     Zone  4 = -34C/-29C    -30F/-20F
     Zone  5 = -29C/-23C    -20F/-10F
     Zone  6 = -23C/-18C    -10F/  0F
     Zone  7 = -18C/-12C     0 F/+10F 
     Zone  8 = -12C/- 7C    +10F/+20F
     Zone  9 = - 7C/- 1C    +20F/+30F
     Zone 10 = - 1C/+ 4C    +30F/+40F
     Zone 11 =  above+4C/        +40F

Average Zone Frost Dates 

NOTE: The dates below are for the Northern Hemisphere


Zone  1 = Average dates Last Frost  = 1  Jun / 30 Jun
          Average dates First Frost = 1  Jul / 31 Jul
          Note: vulnerable to frost 365 days per year          
          
Zone  2 = Average dates Last Frost  = 1  May / 31 May
          Average dates First Frost = 1  Aug / 31 Aug

Zone  3 = Average dates Last Frost  = 1  May / 31 May
          Average dates First Frost = 1  Sep / 30 Sep
          
Zone  4 = Average dates Last Frost  = 1  May / 30 May
          Average dates First Frost = 1  Sep / 30 Sep
          
Zone  5 = Average dates Last Frost  = 30 Mar / 30 Apr
          Average dates First Frost = 30 Sep / 30 Oct

Zone  6 = Average dates Last Frost  = 30 Mar / 30 Apr 
          Average dates First Frost = 30 Sep / 30 Oct 

Zone  7 = Average dates Last Frost  = 30 Mar / 30 Apr 
          Average dates First Frost = 30 Sep / 30 Oct 
          
Zone  8 = Average dates Last Frost  = 28 Feb / 30 Mar 
          Average dates First Frost = 30 Oct / 30 Nov 

Zone  9 = Average dates Last Frost  = 30 Jan / 28 Feb 
          Average dates First Frost = 30 Nov / 30 Dec

Zone 10 = Average dates Last Frost  = 30 Jan or before
          Average dates First Frost = 30 Nov / 30 Dec

Zone 11 = Free of Frost throughout the year.

Frost Definitions:

Frost:		Light Freeze. damage depends upon 
                	length of frost duration.

Light Freeze: 	-2C/-0C OR 29F/32F - tender plants  
		killed with little destructive 
		effect on other vegetation.

Moderate Freeze:-8C/-2C OR 25F/28F - wide destruction 
		on most vegetation with heavy 
		damage to fruit blossoms and  
		tender semi-hardy plants.

Severe Freeze:	-9C OR 24F and colder, heavy damage 
  		to most plants.

Sunlight Definitions:

Shade:	  Usually an area under a closed tree canopy 
          	  that receives no direct sun at all.

Partial   Usually an area under a lone or limited 
Shade:    number of trees receiving only a 1 to 5  
          hours of dappled sun during the day.

Partial   Usually refers to an area that receives  
Sun:      approximately 3 - 5 hours of full 
	  sun per day.

Full Sun: Refers to an area receiving 6 or more 
          hours of full sun per day.