Planting & Growing Zones in the USA: 2019 Guide

Here are a few examples of gardening failures that I have personally had:

• I planted a patch of gladiolus that didn’t come back the next year.
• I had hydrangeas that would not bloom.
• I tried to grow a windmill palm and it died.

I had these problems because I did not fully understand what planting & growing zone I lived in.

I created this guide to help you learn what planting zone you live in. It has helped me and I hope it helps you as well.

What is a Planting Zone?

A planting or growing zone is a geographic area that is defined by the area’s minimum and/or maximum temperatures. A map of these zones helps growers determine if the selected plants will have sufficient cold hardiness and/or heat tolerance to survive.

Types of Planting Zone Maps

Two of the most well-known zone maps are the:

• United States Department of Agriculture (USDA) Plant Hardiness Zone Map
• American Horticultural Society (AHS) Plant Heat Zone Map

The USDA Plant Hardiness Zone Map helps gardeners determine which plants are likely to survive the cold of winter.

The AHS Plant Heat Zone Map is different in that it helps gardeners determine which plants are likely to survive the heat of summer.

About the USDA Plant Hardiness Zone Map

The latest USDA zone map came out in 2012. The map divides the United States into 26 zones, each representing a 5-degree Fahrenheit temperature range for Average Annual Extreme Minimum Temperature. In simple terms, this map shows you “how cold it gets where you live.”

How to Read the USDA Plant Hardiness Zone Map

There are two ways to use the map. You can either:

• Look at the maps and find your zone using the color-coded legend.
• Enter you zip code in the Zip Code tool on the USDA map page.

About the AHS Plant Heat Zone Map

The latest that I can find came out in 1997. This map divides the United States into 12 zones. These zones indicate the Average Number of Days Per Year Above 86 Degree Fahrenheit.
The map was created by analyzing National Weather Service (NWS) daily-high temperatures recorded between 1974 and 1995.

The AHS Plant Heat Zone Map is copyrighted and cannot be shown here. It can be purchased from the American Horticultural Society.

Growing & Planting Zone Information by State

In this section I have individual USDA state zone maps. You can click on these maps to open up larger versions.

I am working to add detailed zone-map information for each state.

The state of Alabama contains 5 planting zones:

• Northern parts of Jackson and Dekalb counties are zone 7a.
• Most of North Alabama down to around Birmingham are in zone 7b. Cities in zone 7b include Birmingham, Huntsville, Decatur, Gadsden, and Talladega.
• Most of South Alabama south of Birmingham is in zone 8a. Cities in zone 8a include Montgomery, Tuscaloosa, and Auburn.
• Some southernmost areas of Alabama are zone 8b. Cities in 8b include Mobile and Dothan.
• The Gulf Coast area around Gulf Shores is in zone 9a.

The state of Alaska has 16 planting zones! This is more than any other state in the United States.

• Most of Far North Alaska above the Arctic Circle is in zones 1a–2b. Barrow is in this area.
• Interior Alaska which is located centrally in Alaska is a little warmer than the Far North and is in zones 1a–3b. Fairbanks is in this area.
• The Western Arctic area around Nome Alaska is in zones 2a–3b.

Southern Alaska is where it gets really interesting. The Pacific Ocean warms up many areas here. The zones range from 2a – 8b. The Aleutian Islands and islands within the Inside Passage can be in the same zone as South Alabama! That is amazing.

• Anchorage is in zones 4a–5b.
• Juneau is in zones 6a–6b

The state of Arizona contains 13 planting zones.

The state of Arkansas has 4 planting zones.

California – CA

California is in USDA Plant Hardiness Zones 5a–11a.

The state of California has 13 planting zones.

Texas – TX

Texas is in USDA Plant Hardiness Zones 6b–10a.