No matter if it is a flower garden, fruit, or vegetable garden, or even a remix of various plants, trees, potatoes and flowers, you will need to outline a well-thought out plan that involves plant zones (plant hardiness zones) and a planting zones map, among other climate-related aspects. In this guide, you will learn:

  • what plant zones are;
  • what the USDA planting hardiness zones refer to;
  • how to consult a planting zones map.
USDA Plant Hardiness Zone Map photo

The USDA Plant Hardiness Zone Map.

We all dream of designing our very own picturesque garden to come home to every day. The concept of growing your own produce or flowers doubles as a healthy lifestyle and a fun hobby for almost any individual from anywhere in the world. Nonetheless, every gorgeous garden has lots of hard work, thought and care behind it, so you have to go through some essential steps beforehand.

What Are Plant Hardiness Zones?

If you are a beginner in the world of gardening, you might be wondering what plant zones, plant hardiness zones or planting zone maps are. These are not terms that are normally understood by an individual who has experimented with gardening before, so you do not need to worry. However, you will need to become familiar with this terminology in order to design a beautiful, blossoming garden.

First and foremost, we need to clear up what hardiness plant zones are. To put it in a nutshell, hardiness plant zone maps indicate the weather/ climate conditions in specific areas in the world. Formally speaking, the USDA planting hardiness zones map is ‘based on the average annual minimum winter temperature, divided into 10-degree F zones’, according to their official website.

Formally speaking, the USDA (United States Department of Agriculture) planting hardiness zones map is ‘based on the average annual minimum winter temperature, divided into 10-degree F zones’, according to their official website.

A planting zones map basically works as a finder, schedule, or chart for individuals who garden or grow plants – through plant zone maps they can see what plants will live out in their area and which will not.

You can clearly understand why a map with zones for planting is essential to a gardener. Without one, their plants will die out during cold seasons, resulting in a loss of time, money and a general dissatisfaction with their work.

Planting zones maps are available for various regions around the world, from North America (USA and Canada), the UK, Australia, China, Africa, and anywhere else on the globe.

We will continue with planting zones for the US, but residents who live in Ontario, for example, can access the Canadian planting hardiness zones map on the official Natural Resources Canada website here.

Examples of Planting Zones

Now that we are on the same page with these kinds of maps, we will continue with a few examples of popular planting zones that people are generally looking for in the U.S. All of the data included in our guide is provided by the United States Department of Agriculture – Agricultural Research Service, through the 2012 USDA Plant Hardiness Zone Map.

southern california plant hardiness zone map

The USDA Plant Hardiness Zone Map for Southern California.


Due to the fact that California is such a large state, its average minimum temperature varies, according to the northern and southern parts. For example, the south part of California covers a wide range of averages, from large portions in the 8 hardy code (8a and 8b) in the lower central and east regions (as well as both 9 indications – 9a and 9b), to 10 a, 10b and even 11 a areas in the farthest southwest corner in the Orange county intertidal zone.

Approaching central California, you will also see 6a and 6b regions, as well as some sports of 5 a and 5b. Northern California is mainly a 9b zone, especially in the area surrounding Sacramento, but also has plenty of 6 zones alongside the eastern border. You can follow all of these planting zones and indications in the image we have provided in our article.


Going across the country to the east coast, Florida has just a few main planting zones that range from 8 (10 to 15 degrees average annual extreme minimum temperature) to 11a (40 to 45 degrees minimum temperature average). Naturally, the temperatures rise as you go into the southern part of Florida, with the highest numbers in the Fort Lauderdale and Miami areas.


Texas, being the largest of all states, also has a wide range of hardiness planting zones. On the USDA website, the specific regions are separated into East and West Texas, with the former containing zones 7b, 8a, 8b, 9a, 9b and 10a and the latter 6b, 7 a, 7b, 8a, 8b and 9a. The largest portion of Texas (mainly all across the center strip) is an 8a zone, but there are also large portions that fall under 8b and 9a.


The state of Colorado is a predominantly 5b zone, with an average annual extreme minimum temperature of -15 to -10 degrees between 1976 and 2005, but also contains a large 6b (-5 to 0 degrees) in the southeast region of the state. Residents in Park, Gunnison, Jackson and Grand counties should take note of the 3 a, 3 b and 4 a zones, as temperatures in these areas have dropped to an annual average between -25 and -40 degrees.

New York

The Big Apple has a general area that identifies as a 5b zone (-15 to -10 degrees), with centers of 5a (-20 to -15). The northern part of New York, however, has 4a (-30 to -25 degrees) and 3b (-35 to -30 degrees) zones that residents should be aware of.

Tennessee, Michigan, Ohio and all other United States can be consulted on the USDA Plant Hardiness Zone Map, where you can also search by zip code for the best results (my advice is to use this tool). I am certain that you will get around the website with ease, as it was designed to be user-friendly. When you access the website, simply enter your zip code in the designated field and press Find.

If you want core details about your area, you can ask your local county extension agent office or the agricultural college of your state for the latest details on plant hardiness zones.

Understanding Climates

After you have checked the numbers and statistics, it helps to put the pieces of the puzzle together with a bit of information about climates. Even though you have already gone through these details in school at one point, it is best to revisit them as an adult, especially if you are interested in taking up gardening.

There are several classification systems for climates that have been developed, but the most accepted one on a global level is the Koppen climate classification. It identifies climates in five distinct groups, from A to E:

  • Tropical (mega thermal) climates;
  • Dry (semiarid and arid) climates;
  • Temperate (mesothermal) climates;
  • Continental (microthermal) climates;
  • Polar and alpine climates.

Each group has several climates that affect the way animals and plants live and thrive in these areas. Climates are strongly connected to hardiness zones, as the characteristics of each climate directly affect the way plants grow in the area.

Once you have identified where your region stands in means of plant hardiness, you can proceed by designing your garden with the species that are suitable for your climate.

Image sources: 1, 2.

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