USDA Hardiness Zones and Gardening

November 18, 2023
Blain's Farm & Fleet

Find out which USDA hardiness zone you’re in before starting a garden.

USDA hardiness zones help you know which plants grow best in different parts of the country. This is an important thing to know when considering starting a garden.

Have you ever thought about which plants will flourish in your region? While you may have a plan for where you want your plants and what you think looks best, it’s important to consider the specific needs of your chosen flora.

Blain’s Farm & Fleet is here to provide you with the necessary information you need to determine what fruits, vegetables, flowers, and more will thrive in your yard!

The United States is a huge country, spanning from the Atlantic to the Pacific. From its dry deserts filled with cacti, to areas of grassy plains, to subarctic and tropical regions, the plants you’ll find vary greatly as you go about from region to region.

Why Are The USDA Hardiness Zones Important?

USDA plant hardiness zones show the average of extreme minimum temperatures for an area, calculated from the lowest daily minimum temperature recorded. This does not represent the coldest it has ever been or ever will be in an area. It simply is the average of lowest winter temperatures for a given location for this time period.

This is important to consider when choosing the best plants for your area because some plants survive better in colder temperatures than others.

This is also important to know for both rural and urban planters, as each of these areas have many factors that can affect the temperature.

Cities hold more heat because there is more blacktop and concrete, so a city may have a higher zone than the surrounding rural areas. Areas with higher elevation tend to be colder than surrounding low laying areas, so they may have a cooler zone. Locations near a large body of unfrozen water may have milder winter weather and will be considered to be in a warmer zone.

This means that someone living in a city probably won’t be planting many of the same fruits and vegetables in their garden bed, for example, than someone living near the mountains would be in their home garden.

USDA Hardiness Zones

USDA hardiness zones range from 1 (coldest) to 13 (warmest). Each zone has a 10 degree difference between them. The zones also have two sections, “a” and “b,” which have a five degree difference between them.

Here is a list of all of the zones as named by the USDA, with their temperature ranges and a few examples of cities that reside in these zones.

USDA Zones Temperature RangesExample Cities
Zone 1a -60° F to -55° F
Fort Yukon, Alaska
Zone 1b -55° F to -50° FAlaska North Slope
Zone 2a -50° F to -45° F
Fairbanks, Alaska
Zone 2b -45° F to -40° F
Buckland, Alaska
Zone 3a -40° F to -37.2° F
Denali, Alaska
Zone 3b -35° F to -30° F
International Falls, Minnesota
Zone 4a
-30° F to -25° F
Hayward, Wisconsin
Zone 4b -25° F to -20° FEau Claire, Wisconsin
Zone 5a -20° F to -15° FFort Dodge, Iowa
Zone 5b-15° F to -10° FMadison, Wisconsin
Zone 6a-10° F to -5° FLansing, Michigan
Zone 6b-5° F to 0° FBuffalo, New York
Zone 7a0° F to 5° FHarrisburg, Pennsylvania
Zone 7b5° F to 10° FNashville, Tennessee
Zone 8a10° F to 15° FAtlanta, Georgia
Zone 8b
15° F to 20° FDallas, Texas
Zone 9a20° F to 25° FSan Antonio, Texas
Zone 9b25° F to 30° FSacramento, California
Zone 10a30° F to 35° FOrlando, Florida
Zone 10b35°F to 40° FLos Angeles, California
Zone 11a40° F to 45° FMiami, Florida
Zone 11b45° F to 50° FFlorida Keys, Florida
Zone 12a50° F to 55° FWahiawa, Hawaii
Zone 12b55° F to 60° FHonolulu, Hawaii
Zone 13a60° F to 65° FSan Juan, Puerto Rico
Zone 13b65° F to 70° FIsla Verde, Puerto Rico

Thing to Consider Before Planting

Remember that the USDA hardiness zones are simply a tool to help gardeners choose the best plants for their area. This is by no means an absolute, and many plants can grow in different zones.

Make sure you are doing your research before you buy plants and vegetable seeds for your garden. Blain’s Farm & Fleet can aid in your research by providing more gardening tips and information in our Gardening Blog.