USDA Hardiness Zones

Choosing the right plants for your region's zone is important for the health and growth of your garden. When you select plants well-suited to your location, they will perform well and thrive.

Many factors must be considered; cold, heat, humidity, and rainfall affect a plant’s ability to thrive.

The USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which perennial plants are most likely to thrive at a location.

The Hardiness Zone Map is a helpful tool for determining a plant’s survivability.

 

Hardiness Zone Map

 

USDA Cold Hardiness Zone Map

First published in 1960 and updated in 1990, 2012, and 2023, the map is based on the average annual minimum winter temperature, divided into 10°F zones.

The map is available as an interactive GIS-based map. Users may also type in a ZIP Code and find the hardiness zone for that area.

Using the map to find the zone where you live, you can determine which plants will withstand these average minimum temperatures.

https://planthardiness.ars.usda.gov

  

Zones, Annuals and Perennials

USDA Hardiness Zones play a role in categorizing annual and perennial plants.

An annual plant adds quick color, structure, or texture to your garden or containers for just one season. Sometimes, you'll find these marked as "seasonal" at garden centers.

A perennial, however, is a plant that will return year after year when grown in the appropriate USDA Hardiness Zone and conditions.

If a plant is sold as an annual, it is frost-sensitive and will only last until your first frost. There are some frost-hardy annuals, but these are generally still sensitive to freezing temperatures and will be damaged after your first freeze.

Most annuals can be grown as perennials in warmer climates (Zones 10-13); just be sure to check the USDA Zone on the plant tag or webpage to be sure.

 

Limitations

Since the USDA zones are based on average temperatures, it is still possible to have extreme weather events that are too cold for a plant to survive, even if it is hardy in your zone.

The USDA zones do not take summer high temperatures into consideration. Zone maximums listed on plants are not based on USDA data and are general guidelines based on a plant's tolerance to higher temperatures.

Since there are many factors that the USDA zones do not account for, it is just one element to consider when choosing a plant for your garden. Your local garden center is the best way to find plants adapted to your local climate's humidity, high temperatures, and other weather patterns.

 

 

 

 

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