Remember the old saying “If the mountain will not come to Muhammad, then Muhammad must go to the mountain?” The past gardeners’ version of that was if you wanted to garden in a more mild climate, then pack up your wheelbarrow and move South. Well, not any more. The mountain is coming to Muhammad, in the form of milder climate coming to northern gardeners.
The movement of a milder gardening climate northward was made official when the United States Department of Agriculture updated it’s Plant Hardiness Zone map in 2012 from the 1990 version, including the latest 30 years of weather data in the newer version. The 2012 version shifted most regions a half-zone warmer. For example, most of North Dakota was zone 3 ever since the zone system originated nearly 60 years ago. Now, almost three-fourths of North Dakota is considered zone 4. (zone 10 is the warmest, zone 1 is the Arctic coldest.)
Here is an interesting graphic that shows the movement of the warmer zones northward. Locate and click on the “Play” button, and watch how the zones moved. https://www.arborday.org/media/mapchanges.cfm
So what will the future hold? Well, in the immediate gardening present, our region is seeing the first frost of autumn coming later. Many locations didn’t receive killing frost until October. The first autumn frost in Fargo is now averaging September 30, instead of the past’s mid-September average.
Will warmer hardiness zones continue to march northward? Here is an interesting prediction by plant zone climatologists. Zone 5 is currently unheard of in Minnesota. Notice the 30-year prediction of a good chunk of Minnesota basking in zone 5. And notice how zone 5 is projected to march through South Dakota, heading for North Dakota.
Heck, I might live to see North Dakota and Minnesota truly in the Banana Belt.