AmericanFarm.com

Up on new planting zones? (Editorial)

It’s called the Plant Hardiness Zone Map, and the USDA has released a new one which, as you might suspect, shows it’s getting a little warmer, like everywhere.
The PHZM, as it is referred to in government-ese, is the product of the USDA’s Agricultural Research Service and Oregon State University’s Climate Control Group.
It is a new version, updating a 1990 map, and is described as “the most sophisticated Plant Hardiness Zone Map yet for the United States.”
Compared to the 1990 version, officials reported, zone boundaries in this edition of the map have shifted in many areas.
The new map is generally one 5-degree-Fahrenheit half-zone warmer than the previous map throughout much of the United States.
This is mostly a result, they said, 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 for 1976-2005.
In contrast, the 1990 map was based on temperature data from only a 13-year period of 1974-86.
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 in the past you could buy poster-sized copies of the map from the USDA, not this year.
This year, anyone may download the map free of charge from the Internet onto a personal computer and print copies of the map as needed.
For more information, visit www.planthardiness.ars.usda.gov.
Once the map is displayed, click on an individual state to see more specific details for that area.
It is clear that weather patterns have changed, and in many cases become more violent.
It is also clear that the only thing we can do about it for the most part, is to map those changes.
Still that is a useful exercise for commercial seed growers and farmers and plant breeders and others who take average temperatures — the highs and the lows — into their calculations.