What Does My USDA Planting Zone Mean?

by on December 31, 2011

UrbanFig: USDA Plant Hardiness Zone MapUSDA planting zones are listed everywhere from books to plant tags and sometimes they can get confusing especially for the novice urban gardener. In this post we are going to look at what the zones are, how they are created and what they mean to gardeners.

What is the USDA Plant Hardiness Zone Map?

The USDA created a Plant Hardiness Zone Map in 1990 that divides the country into 11 zones, each separated by approximately 10 degrees in temperature. To further complicate things, some zones (like mine in Alabama) are further broken down into a and b zones.

Why do we need zones?

By breaking the country into zones of similar temperatures it is easier for plant companies to designate whether or not a plant is ideal for where you live. A plant that might thrive in one zone may struggle in another, and zone designations are a quick reference point.

Are there limitations to planting zones?

Many. The USDA Plant Hardiness Zone Map is fairly reliable for those of us on the east coast, but for Carol and the rest of you to the west, the information is far less reliable. As an example, Seattle, Washington and Phoenix, Arizona are in the same USDA zone, zone 8. Any bets on how different the gardens are in these two places? In the east, most places with similar temperatures and climates grow similar plants while on the west coast that is often not the case.

That said, knowing your USDA zone is a good starting point toward learning what will (and will not) work in your area. If you have specific questions though, it is best to ask someone with experience in your area and not just your zone. With Carol on the west coast and me in the east, one of us will usually be able to help.

Here on UrbanFig we will provide information that goes beyond your zone and give specifics about temperature and climate as often as possible to avoid confusion. If you have any questions please let us know. You can leave a comment here or email me at any time at and I’ll do my best to steer you in the right direction.

{ 3 comments… read them below or add one }

Plant Maps January 2, 2012 at 7:15 AM

There is an interactive version of the USDA hardiness zone map at

There is also a zone to zipcode search tool available to find your zone


Eleanor Fairman October 28, 2017 at 11:08 AM

I received a daphne, Eternal Fragrance for my birthday this summer. I live in zone 7, Yakima, WA east of the Cascades so a different climate than Seattle. My two plants are in two large pots so I am able to move them. My question, how much cold will they take this winter. Shall I move them to a covered, open patio? Cover the bottom with compost or totally cover them with something? They’ve grown so well since I planted them, it would be difficult to lose them though the winter. Any help you can give me will be greatly appreciated.


Carol June 17, 2021 at 9:24 AM

We don’t specialize is flowering plants, just edibles. Thanks for visiting


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