Continental United States: Zones 3-10
The USDA Plant Hardiness Zone Map shows the standard growing zones. Use
the map to determine which plants are most likely to thrive in your
region.
Plant hardiness is very important to growing success. Check the map to determine which hardiness zone you live in to find your zone. You'll find zone designations at the end of many of the seed directory descriptions on this website. A variety marked "Zones 3-8," for example, should grow and thrive in zones 3, 4, 5, 6, 7 and 8.
USDA Newest Zone Map Version
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| 2012 update of the Hardiness Zone Map |
Hardiness zone
A hardiness zone is a geographic area defined to encompass a certain range of climatic conditions relevant to plant growth and survival.
The original and most widely-used system, developed by the United States Department of Agriculture (USDA) as a rough guide for landscaping and gardening, defines 13 zones by annual extreme minimum temperature. It has been adapted by and to other countries (such as Canada) in various forms.
Unless otherwise specified, "hardiness zone" or simply "zone" usually refers to the USDA scale. For example, a plant may be described as "hardy to zone 10": this means that the plant can withstand a minimum temperature of -1°C (30.2°F) to 3.9°C (39.0°F).
Other hardiness rating schemes have been developed as well, such as the UK Royal Horticultural Society and US Sunset Western Garden Book systems.
The original and most widely-used system, developed by the United States Department of Agriculture (USDA) as a rough guide for landscaping and gardening, defines 13 zones by annual extreme minimum temperature. It has been adapted by and to other countries (such as Canada) in various forms.
Unless otherwise specified, "hardiness zone" or simply "zone" usually refers to the USDA scale. For example, a plant may be described as "hardy to zone 10": this means that the plant can withstand a minimum temperature of -1°C (30.2°F) to 3.9°C (39.0°F).
Other hardiness rating schemes have been developed as well, such as the UK Royal Horticultural Society and US Sunset Western Garden Book systems.
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| Temperature scale used to define USDA hardiness zones. These are annual extreme minimums (an area is assigned to a zone by taking the lowest temperature recorded there in a given year). As shown, the USDA uses a GIS dataset averaged over 1976 to 2005 for its United States maps. |
Zone Map United States hardiness zones
The USDA system was originally developed to aid gardeners and landscapers in the United States.
State-by-state maps, along with an electronic system that allows finding the zone for a particular zip code, can be found at the USDA Agricultural Research Service (USDA-ARS) website.
The low latitude and often stable weather in Florida, the Gulf Coast, and southern Arizona and California, are responsible for the few episodes of severe cold relative to normal in those areas. In the United States, most of the warmer zones (zones 8, 9, 10, and 11) are located in the southern half of the country and on the Pacific coast. The more northerly and central portions of the USA have the cooler zones (zones 7, 6, 5, and 4). The central and northerly portions of the mainland often have much less consistent range of temperatures in winter due to being more continental, and thus the zone map has its limitations in these areas.
U.S. Plant Hardiness Zone Map
