U.S. Hardiness Zones

What Are Hardiness Zones?

The Plant Hardiness Zones divide the United States and Canada into 11 areas based on a 10 degree Fahrenheit difference in the average annual minimum temperature. (The United States falls within Zones 2 through 10). For example, the lowest average temperature in Zone 2 is -50 to -40 degrees Fahrenheit, while the minimum average temperature in zone 10 is +30 to +40 degrees Fahrenheit.

Use the form below (courtesy of ArborDay.org) to input your zip code and find out your Hardiness Zone.

When you are considering trees to use as bonsai, often you'll see a range of zones indicated. If your zone is within the range, and you're planning on growing your bonsai outdoors, that tree would be a good choice! If you're going to grow your trees indoors, the Hardiness Zones can pretty much be ignored, as most homes tend to be the equivalent of Hardiness Zone 10-11 year-round.