USDA Maps Out New Plant Hardiness Zones

New USDA Cold Hardiness Zone map

The USDA has released the new version of its Plant Hardiness Zone Map (PHZM), updating a useful tool for gardeners and researchers for the first time since 1990 with greater accuracy and detail. The new map—jointly developed by USDA’s Agricultural Research Service (ARS) and Oregon State University’s (OSU) PRISM Climate Group—is available online at www.planthardiness.ars.usda.gov

For the first time, the new map offers a Geographic Information System (GIS)-based interactive format and is specifically designed to be Internet-friendly. The map website also incorporates a “find your zone by ZIP code” function. Static images of national, regional and state maps also have been included to ensure the map is readily accessible to those who lack broadband Internet access.

“This is the most sophisticated Plant Hardiness Zone Map yet for the United States,” said Catherine Woteki, USDA Under Secretary for Research, Education and Economics. “The increases in accuracy and detail that this map represents will be extremely useful for gardeners and researchers.”

Plant hardiness zone designations represent the average annual extreme minimum temperatures at a given location during a particular time period. They do not reflect the coldest it has ever been or ever will be at a specific location, but simply the average lowest winter temperature for the location over a specified time. Low temperature during the winter is a crucial factor in the survival of plants at specific locations.

The new version of the map includes 13 zones, with the addition for the first time of zones 12 (50°F to 60°F) and 13 (60°F to 70°F). Each zone is a 10°F band, further divided into 5°F Fahrenheit zones “A” and “B.”

To help develop the new map, USDA and OSU requested that horticultural and climatic experts review the zones in their geographic area, and trial versions of the new map were revised based on their expert input.

Compared to the 1990 version, zone boundaries in this edition of the map have shifted in many areas. The new map is generally one 5°F half-zone warmer than the previous map throughout much of the United States. This is mostly a result of using temperature data from a longer and more recent time period; the new map uses data measured at weather stations during the 30-year period 1976-2005. In contrast, the 1990 map was based on temperature data from only a 13-year period of 1974-1986.

However, some of the changes in the zones are a result of new, more sophisticated methods for mapping zones between weather stations. These include algorithms that considered for the first time such factors as changes in elevation, nearness to large bodies of water, and position on the terrain, such as valley bottoms and ridge tops. Also, the new map used temperature data from many more stations than did the 1990 map. These advances greatly improved the accuracy and detail of the map, especially in mountainous regions of the western U.S. In some cases, they resulted in changes to cooler, rather than warmer, zones.

While about 80 million American gardeners, as well as those who grow and breed plants, are the largest users of the USDA Plant Hardiness Zone Map, many others need this hardiness zone information. For example, the USDA Risk Management Agency uses the USDA plant hardiness zone designations to set some crop insurance standards. Scientists use the plant hardiness zones as a data layer in many research models such as modeling the spread of exotic weeds and insects.

Although a poster-sized version of this map will not be available for purchase from the government as in the past, anyone may download the map free of charge from the Internet onto their personal computer and print copies of the map as needed.

Leave a Reply

Featured Stories
Port Tampa Bay shipping channel
Citrus
May 24, 2016
Panama Canal Expansion To Bring Trade Opportunities To Florida
Agriculture Commissioner Adam Putnam says a confluence of events is putting the state's producers in a good spot to open new markets. Read More
anti-GMO corn spoof via social media
Citrus
May 24, 2016
Social Media Posts On GMOs Falling Flat [Opinion]
Hopefully, the hysteria the West has perpetuated on genetic engineering will not stifle the potential of moving our production forward enough to help feed a growing global population. Read More
Photo credit: USDA
Fruits
May 24, 2016
Organic Food Sales Hit Record $43.3 Billion In 2015
Organic Trade Association says organic fruits and vegetables logged sales of $14.4 billion. Read More
CA- Winegrape Vineyard
Grapes
May 24, 2016
Sea Change Coming To California Winegrape Landscape
Vines continue to be pulled from the state’s interior, while planting is expected to increase along coast and in Delta area. Read More
non-gmo label leafy greens
Citrus
May 24, 2016
Report Says GMOs Offer No Risk To Human Health
The study stresses the need for proper resistance management, the need for a different ways to evaluate all new crop varieties, regardless of process in which they were developed. Read More
Florida Ag Commissioner Adam Putnam checks out prepared school lunches. School meals are looking more colorful these days as fresh produce finds a place on the tray.
Citrus
May 24, 2016
Full-Time Effort Required To Feed Farm-To-School Programs
Florida Commissioner of Agriculture Adam Putnam gives a shout-out to those providing fuel to kids during the school year as well as the summer months. Read More
Photo credit: USDA
Citrus
May 23, 2016
World Health Organization Experts: Glyphosate Not Carcinogenic
Risk unlikely when consuming crops treated with herbicide. Read More
Food safety meeting for growers in Florida
Citrus
May 23, 2016
Florida Growers Putting Food Safety On Front Burner
Specialty crop industry stakeholders hungry to understand what’s ahead as FDA begins implementing new food safety rules. Read More
Example of cucurbit yellow stunting disorder virus
Cucurbits
May 21, 2016
Cucurbit Yellow Stunting Disorder Virus Cases Flaring In South Florida
Learn how to identify, the survival and spread, as well as management methods for this vegetable disease. Read More
nutcracker crunching down on a walnut
Nuts
May 20, 2016
Bank Predicts A Roller Coaster Ride For Tree Nut Industry
Supply expected to grow by more than one-third in next five years, but decreasing demand may lower prices. Read More
The Latest
Citrus
May 24, 2016
Panama Canal Expansion To Bring Trade Op…
Agriculture Commissioner Adam Putnam says a confluence of events is putting the state's producers in a good spot to open new markets. Read More
Citrus
May 24, 2016
Social Media Posts On GMOs Falling Flat …
Hopefully, the hysteria the West has perpetuated on genetic engineering will not stifle the potential of moving our production forward enough to help feed a growing global population. Read More
Fruits
May 24, 2016
Organic Food Sales Hit Record $43.3 Bill…
Organic Trade Association says organic fruits and vegetables logged sales of $14.4 billion. Read More
Grapes
May 24, 2016
Sea Change Coming To California Winegrap…
Vines continue to be pulled from the state’s interior, while planting is expected to increase along coast and in Delta area. Read More
Citrus
May 24, 2016
Report Says GMOs Offer No Risk To Human …
The study stresses the need for proper resistance management, the need for a different ways to evaluate all new crop varieties, regardless of process in which they were developed. Read More
Citrus
May 24, 2016
Full-Time Effort Required To Feed Farm-T…
Florida Commissioner of Agriculture Adam Putnam gives a shout-out to those providing fuel to kids during the school year as well as the summer months. Read More
Citrus
May 23, 2016
World Health Organization Experts: Glyph…
Risk unlikely when consuming crops treated with herbicide. Read More
Citrus
May 23, 2016
Florida Growers Putting Food Safety On F…
Specialty crop industry stakeholders hungry to understand what’s ahead as FDA begins implementing new food safety rules. Read More
Cucurbits
May 21, 2016
Cucurbit Yellow Stunting Disorder Virus …
Learn how to identify, the survival and spread, as well as management methods for this vegetable disease. Read More
Nuts
May 20, 2016
Bank Predicts A Roller Coaster Ride For …
Supply expected to grow by more than one-third in next five years, but decreasing demand may lower prices. Read More
Insect & Disease Update
May 20, 2016
Yara International Pledges $100,000 To S…
Scholarship will fund University of Florida undergraduate and graduate students. Read More
Citrus
May 20, 2016
Florida Farmland Becoming Big Deal For I…
Real estate values in the Sunshine State dictated by money looking for a home. Read More
Citrus
May 19, 2016
Bayer Makes Bid For Monsanto
Monsanto says proposal is being reviewed by board of directors as well as legal and financial advisors. Read More
GenNext Growers
May 19, 2016
Get To Know Rory Crowley Of The Almond L…
The assistant operations manager and director of business and research development for the Nicolaus Nut Company, Rory Crowley talks about how the Almond Leadership Program helped him prepare for the future. Read More
Disease Control
May 19, 2016
Native Plants Reduce Need For Vineyard W…
Scientists in eastern Washington are finding drought-tolerant alternatives to roses at the end of vineyard rows that not only save Read More
Grapes
May 18, 2016
Minnesota Has New Cold-Hardy, Lower-Acid…
The University of Minnesota has released a new cold-hardy grape that holds promise for winemakers wanting to make dryer wines Read More
Farm Management
May 17, 2016
Tour De Fresh Cycling Event Will Raise F…
The goal for 2016 is to place 50 additional salad bars in schools across the country. Read More
Citrus
May 17, 2016
$130 Million In Funds For Fruit And Vege…
USDA allocates funds for Extension, organic production, food safety, and technology grants. Read More
[gravityform id="62" title="false" description="false"]