What’s a hardiness zone and how do I find mine?

The USDA Plant Hardiness Zone Map is the standard by which gardeners can determine which plants are most likely to thrive in their location. The map divides the United States and Canada into zones based on the average annual minimum temperature for that area.

This information is particularly useful when purchasing seeds, plants or trees for your garden. Each plant will bear a tag indicating the zones in which it will best grow. Trying to grow plants that are not suited for your zone will generally result in weak growth, disease, and even complete failure.

There are, of course, exceptions to every rule. Permaculturist Sepp Holzer, for example, has created microclimates on his farm that literally change the hardiness zone allowing him to grow lemons in an alpine climate. It’s exciting and encouraging to know such work is being done, but beyond the scope of this post. We’ll stick to the basics here.Continue Reading