If you love to garden, you’ve probably heard the term USDA Hardiness zone or seen it on plant tags. We include it every time we write about our favorite perennials, shrubs and trees here at PureWow to help you select the right plants for your region. But what does a hardiness zone really tell you— and more importantly, why the heck does it matter?
The first-ever idea of a hardiness zone map was created by Arnold Arboretum of Harvard University in 1927. The most recent version was created by the USDA in 2012 (find your hardiness zone here) and still is the current standard. While other organizations have devised their own versions, they’re not as widely used.
So what makes it the gold standard? And how do you figure out what zone you’re in? Read on for everything you need to know.