Plant Hardiness Zones

Share: 

Rate this Article: 

Average: 3.4 (63 votes)

Which Plants Thrive in Your Region?

Tropical Flower

Plant hardiness zones help gardeners understand which plants will most likely survive at a location.

It is important that your plants can thrive year-round, surviving extreme temperatures.

Note: Zone maps do have shortfalls; if the information is inaccurate, you may live in a microclimate. Soil, moisture, humidity, heat, wind, and other conditions also affect the viability of individual plants.

Here are the most commonly referenced U.S. and Canadian hardiness zone maps:

The USDA Plant Hardiness Zone Map

Considered the standard measure of plant hardiness, the USDA Zone Map is generally  is based on the average annual minimum winter temperature, divided into 10-degree F zones.

Go to the USDA Plant Hardiness Zone Map!

USDA Plant Hardiness Zone Map

Click on above image and it will take you to the USDA Plant Hardiness Zone Map.

Note: This USDA Plant Hardiness Zone Map was updated in January of 2012, the first update since 1990. About half of the country is a half-zone warmer. According to the USDA, this is not a statement on global warming; rather, the scientists are using a differerent set of long-range data and more sophisiticated computers for a more accurate map, especially in challenging areas such as mountain zones which may have been rated too cold or warm in prior iterations. See more detail about the latest map here. And tell us what you think below. Did your zone change?

The Agriculture Canada Plant Hardiness Zone Maps

Unlike the USDA map which is based only on minimum winter temperatures, the Agriculture Canada map considers a wider range of climatic variables, including maximum temperatures and the length of the frost-free period. However, they also provide maps that show plant hardiness zones for Canada based on the USDA extreme minimum temperature approach. Click here for the Agriculture Canada Plant Hardiness Zone Maps.

Agriculture Canada Plant Hardiness Zones Map

Click on above image and it will take you to the Agriculture Canada Plant Hardiness Zones Map.

Flowers, shrubs, trees, and all plants grow best when planted in an appropriate zone! You’ll find that winter damage occurs most when plants are out of their range or “comfort zone.” When you choose plants for a garden or landscape, avoid selecting plants that are marginally hardy for your region; that’s when you’ll see winter damage, poor growth, and a reduction in flowing.

Tip: Planting native species is a surefire way to a stable garden. See our article on, “Natural Landscaping: Go Native!”

More From The Almanac

Comments

Add new comment

Small Flower Gardens for the novice

I am transplanting a Delphinium Guardian Blue to a large outdoor pot. How large of pot do I need, 2, 3 or 5 gallon?

pot size?

You want to move the plant to a pot that will give it room to grow—so it will have a couple of few inches around its base. Too big a pot and it will look out of scale.

Remember, too, that you don’t want the pot to be too big, and so too heavy, to pick up!

Beginner gardner

Hi I'm a beginner gardner and I live in yuma az my zone is 10a what flowers are the best for pots and raised garden beds?

You have an endless list of

You have an endless list of possibilities in your hardiness zone, but just to name a few– Bird of Paradise, Black-eyed Susan, African daisies, Hibiscus, Snapdragon, and Gardenia.

This zone map does not take

This zone map does not take microclimates such as Niagara Falls into consideration. If we were zone 5 we would not be able to grow the tender orchard and vine fruits that we do.

ZONE 7A Niagara orchards & vineyards

Please look more closely at the Natural Resources Canada map ➾ it shows that the regions of the Niagara Peninsula below the escarpment are, in fact, ZONE 7A ➾ not zone 5.

Click on the map or go to www

Click on the map or go to www.planthardiness.gc.ca/?m=1 to see a larger PDF of this map and the different colors around Niagara Falls.

Visit your local county

Visit your local county extension agent office to obtain exact hardiness zone data plus list of plants that thrive in this zone.

You can also contact your state agricultural college for updated info on
state wide hardiness zones.

If there is a master-gardener program in your area get a list of master gardeners and contact one or two of them.

Thanks for sharing and

Thanks for sharing and explaining the change. It’s interesting to see how the zone can shift just 10 miles away.

If I look at the hardiness

If I look at the hardiness Zone map it looks like I'am in zone 7 (light green)on the farmers almanac map. But when I type in my zipcode for farmers almanac it says I am zone 5. Which in my mind is a big difference so How am I to know which zone to go by. Thanks

USDA Map

Hi Edna, First click on the picture of the USDA map. Then, it will take you to the USDA web site. On that site, you can enter your zip code. Here is the direct link to the USDA web site: http://planthardiness.ars.usda...
I hope this helps. --TOFA

Free Almanac Newsletters

Almanac Weekly Companion 

The Almanac.com General Store

Almanac Recipe Box