How to Use the New Online USDA Hardiness Zone Map

A Guide for Knowing What to Plant Where

The new & improved USDA Hardiness Zone Map, now available online.
The new & improved USDA Hardiness Zone Map, now available online. | Source

Why consult a hardiness zone map?

Many factors will affect a plant's success in your landscape—soil quality, sunlight, humidity, water and temperature among them.

When selecting plants, be sure to consider your region's plant hardiness zone. According to the USDA website, hardiness zone designations are derived from "the average annual extreme minimum temperature" in an area over the past 30 years.

Plants that are specified for your zone are more likely than others to survive the normal low temperatures that occur where you live; in fact, many of them may be native to your region.

In 2012, for the first time since 1990, the United States Department of Agriculture (USDA) updated its plant hardiness zone map (PHZM).

Now users can download, save and print national, regional and state PHZMs of the United States through the USDA website.

The USDA's new online hardiness zone map is also available in an interactive version, allowing users to learn about the climate of various parts of the country either by entering a zip code or using the cursor to select locations within the USA.

More importantly, the map has been updated to reflect climatic changes. Has your zone changed?


How to Make Your Own PHZM

Now gardeners can create regional hardiness zone maps like the one above, as well as maps of U.S. states and the nation using the USDA's new online resources.
Now gardeners can create regional hardiness zone maps like the one above, as well as maps of U.S. states and the nation using the USDA's new online resources. | Source
The ZONE GARDEN: A SUREFIRE GUIDE TO GARDENING IN ZONES 8, 9, 10
The ZONE GARDEN: A SUREFIRE GUIDE TO GARDENING IN ZONES 8, 9, 10

Gardening with plants native to your hardiness zone is a great way to create a healthy, low-maintenance garden.

 

New Features

Updated zones Because our climate is changing, so has the USDA Plant Hardiness Zone Map (PHZM). As of 2012, the zones, which according to the USDA are based on the "average annual extreme minimum temperature" of a given area over the past 30 years, were updated to reflect our warmer climate.

New ways to get maps Paper versions of the PHZM are no longer available through the USDA. Instead, users may download and save and/or print the maps themselves at the USDA website.

Online interactive PHZM Now users can access information about zones throughout the U.S.A. by clicking an online interactive version of the PHZM or by entering a zip code.

A PHZM of Your Own

Although the USDA does not offer the new hardiness zone map in print form, you can download and print a national, regional or state map yourself.

To create your own PHZM, click "View Maps" on the USDA homepage, or go directly to the web map page on the USDA website.

Once you're on the web map page, you'll be prompted to select the type of map of the USA you'd like to print (national, regional or state) as well as the resolution you'd prefer (72, 150 or 300 dpi). You'll also be prompted to view the map before printing.

Not interested in a paper copy? That's cool. You can save the map to your computer.

As for reproducing and distributing copies of USDA PHZMs, don't worry about copyright. As a product of U.S. Government, the map is considered part of the public domain. However, "some restrictions do apply," as they say:

1) When copying and/or distributing copies of USDA PHZMs you must leave the USDA-Agricultural Research Service (ARS) and Ohio State University (OSU) logos in place on the maps.

2) If for some reason you alter hardiness zone maps from the USDA (other than changing the format and/or resolution), you must remove the aforementioned logos and clearly display a notice that your new bastardized version of the map is not the official USDA PHZM.

MAKING STATE PHZMs

You can create a PHZM for every U.S. state as well as the District of Columbia and Puerto Rico at the USDA website.
You can create a PHZM for every U.S. state as well as the District of Columbia and Puerto Rico at the USDA website. | Source

How to Make Your Own State Hardiness Zone Map

California & Texas are so large, they have PHZMs each.
California & Texas are so large, they have PHZMs each. | Source

Do you check out a plant's hardiness zone before buying it?

  • Always. I only want plants that survive outdoors without much help from me.
  • Sometimes--although I mostly rely on local retailers. They wouldn't sell plants that won't grow here, right?
  • Never. I don't think it's that important.
See results without voting

To download, print and/or save a map of your state's hardiness zones, click "View Maps" on the USDA Agricultural Research Service homepage.

Select a State

Once you get to the View Maps page, select "State" under "Step 1" in the box to the left of your screen. Then scroll through the list of states, which includes the District of Columbia and Puerto Rico, until you find the one that you want. (Because of their size, California and Texas have two maps each,north and south/east and west, respectively.)

Choose a Resolution

Once you have chosen a state, go on to "Step 2," selecting a resolution. You have three choices, ranging from low to high resolution: Standard (72 dots per inch or dpi); Medium (150 dpi); and High (300 dpi).

Preview, Open & Save

The last step, "Step 3," allows you to preview the map you've created. You may also open it and/or save it to your computer.

Below Step 3 are additional links for creating and printing PHZMs.

MAKING REGIONAL & NATIONAL PHZMs

A simplified national map created at the USDA website in medium resolution.
A simplified national map created at the USDA website in medium resolution. | Source

How to Make Your Own Regional and/or National PHZM

A South West PHZM downloaded from the USDA website at medium resolution.
A South West PHZM downloaded from the USDA website at medium resolution. | Source

Regional maps can be created at the same USDA web page as state PHZMs. At Step 2, simply select "Regional" rather than "State," and then choose from among North Central, North East, North West, South Central, South East and South West. Unfortunately, the regional maps do not include Hawaii, Alaska or Puerto Rico; however, both national maps do.

To create a national PHZM, select "National" in Step 2, and then choose between a map that shows the zones broken down into A and B categories (i.e. Zone 7A, Zone 7B, etc.) and a more simplified national map.

How to Use the Interactive Map Online

The interactive PHZM at the USDA website works best with a broadband Internet connection.

To use the interactive map, go to the home page of "Agricultural Research Service" section of the USDA website. Click "Interactive Map" at the top of the page. A captcha box that contains a challenge-response test will appear. Type in the case-sensitive code in the box to validate that you are indeed a human being, not a computer program, and you'll gain access to the interactive PHZM.

A Succulent for Every Garden

Hardy Succulents: Tough Plants for Every Climate
Hardy Succulents: Tough Plants for Every Climate

Love succulents? No matter what zone you live in, there's a succulent that will grow there. Amazing!

 

To learn about the climate of a given area, either click on the map or enter the zip code in the box next to the red "Locate" button in the upper left-hand corner of the page.

Hold your cursor over the area, and an informational box will appear, providing the area's specific zone, its average low temperature, its average low temperature range, and its latitude and longitude.

Source

About the Author

The Dirt Farmer has been an active gardener for over 30 years.

She first began gardening alongside her grandfather on her parents' farm. Together, they would plant acres of vegetable gardens, setting tomato, eggplant and bell pepper plants; sowing row after row of beans and corn; and building up mounds of soil for white squash, pumpkin, cantaloupe and potatoes.

Today, The Dirt Farmer gardens at home, volunteers at community gardens and continues to learn about gardening through the MD Master Gardener program.

Copyright © 2013 by Jill Spencer. All rights reserved.

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Comments 9 comments

Maren Morgan M-T profile image

Maren Morgan M-T 3 years ago from Pennsylvania

Jill, isn't it amusing that twenty years ago people debated whether the climate was changing? Now it is accepted. I could tell long ago because I could put my tomato plants out earlier and earlier. Great article and I am going to visit the web site. Also, hurray for Ohio State!


The Dirt Farmer profile image

The Dirt Farmer 3 years ago from United States Author

Hi Dolores. I think you'll like the site. It has some cool informational pages in addition to the maps. Take care, Jill


Dolores Monet profile image

Dolores Monet 3 years ago from East Coast, United States

I will check this out. As Radcliff above said, a little distance can make a big change. When my son lived 2 hours south of here, spring flowers bloomed a week or two before they did here. Doesn't seem far, but it made quite a difference.


The Dirt Farmer profile image

The Dirt Farmer 3 years ago from United States Author

No, plants aren't recommended on the USDA site (but what a good idea.) I misunderstood you (I need to read more carefully)--AND I was teasing! Or trying to. Sorry about that! (: --Jill


Radcliff profile image

Radcliff 3 years ago from Hudson, FL

I found our zone using the USDA map like you described--I googled to look for the right plants. Did I miss something? They recommend plants, too? This is entirely possible because I tend to struggle with reading comprehension. LOL


The Dirt Farmer profile image

The Dirt Farmer 3 years ago from United States Author

Hi Rebecca. Yes, so I've been reading. From what I understand, the shift in temperature is only a problem for plants that are iffy for their location in the first place--you know, borderline okay plants that people really want but probably shouldn't grow (not if they want truly carefree plants) in their region.

Thanks for stopping by! --Jill


rebeccamealey profile image

rebeccamealey 3 years ago from Northeastern Georgia, USA

Interesting! I heard a talk radio gardener talking bout this recently. The hardiness zone for some plants are reaching farther to the south, a little. Global warming maybe? Thanks for the information. Great tool to use!


The Dirt Farmer profile image

The Dirt Farmer 3 years ago from United States Author

You'll find that there are microenvironments within the zones, too. Our yard is different from others in our neighorhood, maybe because we're surrounded by woods. The forsythia and daffodils bloom 2-3 weeks later here, and our flowers are blooming long after they've died in the surrounding area. Buy why Google? Click the USDA link in the article, girl, and make sure you're getting the most recent map! Take care, Jill


Radcliff profile image

Radcliff 3 years ago from Hudson, FL

I'm in a weird spot, right on the edge of 9b and 10a. I just Googled the zones and found a nice chart with a list of our native plants. Even a little change in zones must make a significant difference, because the plant life in our town is much different from that of the places just an hour north of here. Thanks again for the great info, Jill :)

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