Most growers rely on a map from the United States Department of Agriculture (USDA) which are known as 'Hardiness Zones'.
It’s a data driven map that tells which plants grow better than others depending on the temperatures, and there have been some big shifts over the past decade.
The map gives us the coldest temperatures every year to let us know which plants will be hardy enough to survive it.
The eastern side of the state saw big changes along Lake Michigan in the Milwaukee and Kenosha areas.
Closer to home here in Central Wisconsin we're not out of the weeds either, especially along the Wisconsin River.
Some plants that historically have grown well in the area can't survive the temperature shift anymore, while others may be able to thrive
Janell Wehr, a Horticulture Educator in Marathon and Wood County said, "The area along the Wisconsin River between Stevens Point and Wausau, that's now showing as a 5A where before it was a 4B. Zone three virtually disappeared from Wisconsin. There's a couple spots left but had major shifts out of zone three or those colder zones and into warmer zones."
So what can gardeners in Central Wisconsin expect when throwing seeds into the earth?
"One of the things that gardeners can expect," Wehr said. "We can use the map as a rule of thumb. It's not going to tell us the coldest temperatures in the given year, but it'll give us a rule of thumb as to what types of plants will be hardy for us. So gardeners can use that indicator of whether or not they can grow zone 4. Perhaps they can even experiment with zone 5 plants."
It's also a good idea to do some research on which plants work best in which zones.
"For gardeners I would suggest really just putting those good gardening practices into play things like mulching things like proper plant spacing, choosing disease resistant varieties as well as purchasing plants from locally sourced vendors," Wehr said.
If you plan to do a garden it’s important to check zones on the map before planting as well as when your plants will be safe from the last frost.
