Alphabetical Plant Listing

Hardiness Zones in the USA

Regional Gardening, USA Hardiness Zones, Plant Hardiness


USDA Hardiness Zones

Based on the minimum ten-year average winter temperatures, plant hardiness zone maps have been progressively developed, first by the Department of Agriculture (USDA) for the United States and then more or less applied to the rest of the planet. The purpose of these hardiness zones is to identify how well plants will withstand the cold winter temperatures of these zones.

  • The USDA Hardiness Zone Map divides North America into 13 zones of 10°F each, ranging from -60°F (-51°C) to 70°F (21°C). If you are planning to buy a shrub, perennial or tree, you need to make sure that this new plant will tolerate year-round conditions in your area. Therefore, to ensure your new acquisition will survive and grow year after year, you will need to compare the hardiness zone of your area with the hardiness zone of your plant (included in most American reference books, nursery catalogs and gardening magazines describing plants).
  • Keep in mind, however, that this USDA map is mostly a guideline. While the USDA map reflects pretty well the garden climates of the eastern half of North America, it does not factor in any elevation or precipitation which have quite an impact in western climates. It does not include micro climates, humidity, summer heat tolerance either.

Selecting plants suited to your climate will be a key step to success. If you know your hardiness zone, find the best plants or exciting garden ideas for your geographic area.

Find the best plants or exciting garden ideas for your hardiness zone


Photo: 123rf

While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.

Find your Hardiness Zone

Find your Climate Zone

Find your Heat Zone

Join Gardenia.net

Create a membership account to save your garden designs and to view them on any device.

Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

Join now and start creating your dream garden!

Create a New Collection

Optional. For your reference.


Move Selected Plants to a Different Collection


Delete Collection

This field is required.