What is Your USDA Plant Hardiness Zone?

What is the USDA Plant Hardiness Zone and what does it matter to you?

The US Department of Agriculture devised Plant Hardiness Zone to help understand how and why plants grow in certain regions, when the best times to grow plants are, the average temperatures of each zone, the average times of first and last frosts, etc.

For the United States, there have been 10 zones (with 10 sub-zones) designated. The zones are based on winter hardiness, plant adaptation, environmental issues (wind, rainfall, moisture, sun, etc.) and typical frost times.

Although there are no hard and fast guarentees (you might get an earlier or later frost than is listed for your zone on a typical year), it does serve as a great reference guide when planning for and planting a garden.

Examples of Zones According to Cities Around the USA:

City	Zone	City	Zone
Anchorage	4	Denver	5-6
Fairbanks	1	Missoula	6
Seattle	8	Minneaplis/St Paul	4
Portland (Oregon)	8	Wichita	6
Sacramento	9	Atlanta	8
Los Angeles	10	Little Rock	7
Honolulu	11	New York City	7
Houston	9	Miami	10-11
Austin	8	Raleigh	8
Phoenix	9	Detroit	5-6
Salt Lake	5	Portland (Maine)	6

For an interactive USDA Hardiness Zone Map, go to The United States National Arboretum website. Here you can click on the area where you live to see what zone you live in.