Hardiness zone map is shifting its way up north

Hardiness zone map is shifting its way up north

Before homeowners and even landscape professionals begin planning their garden design, they’ll first consult the hardiness zone map, which ensures their geographical location can support their growth.

According to a recent poll conducted by the New York Times, readers were asked to describe how they saw climate change affecting their residential properties.

Several homeowners actually reported that they had already begun changing their planting habits due to the warmer weather conditions.

The reason homeowners are now able to change their planting habits can be directly attributed to recent shifts in the hardiness zone map.

What are hardiness zones?

Hardiness zone maps were first developed back in 1938 – representing “the average annual extreme minimum temperatures at a given location during a particular time period”.

In short, it allows growers throughout the United States to easily identify which plants are most ideal for successful growing in their climate based on temperature fluctuations and frost.

Without such a hardiness zone map, plants and crops would freeze to death in some states or never reach their full growing potential based on less than ideal weather conditions.

But the zone maps are changing, and global warming may very well be the culprit.

What that means for the future

According to an analysis by the National Oceanic and Atmospheric Administration , it seems that the plant hardiness zones have moved somewhat dramatically over the last four decades – creeping north to higher latitudes and elevations.

Russell Vose, who leads the Analysis and Synthesis Branch in NOAA’s National Centers for Environmental Information said warming minimum temperatures “might mean I can safely grow things now that I didn’t grow before, but by extension there may be some species that start to naturally grow where I live that didn’t used to grow there,” he said.

While it’s still hard to tell what the environmental impacts will be on the shifting of the United States hardiness zones, for now gardeners are rejoicing in the ability to grow plants, trees and shrubs that once were off limits.