What is my Garden Zone? Using the USDA Hardiness Map

What is my garden zone? Knowing your garden hardiness zone is an important part of planning and planting your garden.

You may have noticed that I often refer to garden zones in my posts. Knowing the answer to the question, what is my garden zone, is an important first step in gardening.

What is my garden zone

I’m actually quite surprised how many people don’t know their garden zone. I guess as a long time gardener I’ve kind of forgotten what it’s like to be new to gardening. So I’m writing this post to help those of you that are just starting out figure out what is my garden zone.

Knowing your garden zone is particularly helpful for year-round gardening.  If you would like to learn more about year-round gardening check out this post!

Finding your garden zone

I will take a minute to explain in this post what a garden zone is and how to use them. But for those of you that just want to jump to the USDA website and grab your garden zone here’s the link. https://planthardiness.ars.usda.gov/

Live in Europe??  Try this map that is fairly similar to the US map and zones:  https://www.gardenia.net/guide/european-hardiness-zones

And for Canada try this map:  https://www.gardenia.net/guide/canadian-hardiness-zones

What is a garden zone

Gardening zones are a helpful first step in learning what to plant and when to plant in your garden. The garden zone map was established by the USDA (United States Department of Agriculture). It often referred to as a plant hardiness map and each zone is determined by the average annual extreme minimum temperature expected in an area. Knowing this extreme low will help you know what plants will survive in the winter.

(map provided by the U.S. Department of Agriculture)
Garden zones are expressed with a number between 1 and 12, with 1 being the coldest and 12 being the warmest. You will notice there is a general trend on the map (see the map here) for the warmer zones to be in the South and for the zones to get colder as you move north. You will also notice the coastal areas are warmer, particularly along the Pacific coast.  There are very few areas in the country at the extremes. The bulk of the country sits in zones 3 to 9 or really even zones 4 to 8 for the largest part of the country. There are no zones 11 or 12 in the Continental US.

So what does a garden zone mean?

Knowing your garden zone can tell you a lot about what can be planted in your garden and when. For example, if you live in zone 5 your maximum low will be around -15 degrees????? So there will be many plants that you just can’t grow outside in your area. Citrus would be a great example, you really can’t grow an orange tree anywhere colder than zone 9 or possibly 8.

Knowing your garden zone can also tell me some fairly solid information about what your weather is overall, if you live in zone 8 then I know you live in a generally warm area with very mild winters, very little frost, and a long growing season. If you live in zone 3 then I know you have very long, cold, and severe winters with an early frost and a very short growing season.

Is the zone system perfect?

The answer to that question is a big NO! There are a whole group of gardeners that are very critical of the USDA zone system. That has caused the USDA to add subzones. So you may often hear someone say they are in zone 5b or 7a.

In our case, the zone listed on the map for Salt Lake City is 7. But ask anyone in our area what is my garden zone and they will tell you 6. Even our extension agents disagree with the USDA and agree we are in zone 6. But then if you add in local microclimates it even gets trickier. For example, we live right at the center of our valley at the lowest point and less than 800 yards from the river. Every winter all the cold air sinks to the low point. We have frost sometimes weeks before our neighbors who live only 5 miles away. I’ve talked to a lot of gardeners who live where we do that feel like they might even be zone 5b.  I’m starting to shy away from that, I think my garden is a solid 6b.

So you can see there is a lot of subjectivity to the system, and it is far from perfect. But the zone system really can be helpful as a starting point.

How do you find your garden zone?

There are hardiness zone maps all over the Internet.  Many Ag colleges even publish their own.

The above image comes directly from the U.S. Department of Agriculture website. As you can see it’s pretty vague and hard to read. But it does give you the general idea, you can see the trend of warmer to colder as you move northward and inland.

But the best way I have found find out “what is my garden zone” is to use the USDA Website. Follow this link. On the top left-hand side, there is a spot for you to add your zip code. This will get you a good idea of your zone.

Next, start talking to your gardening friends and neighbors and see what they think. You may get the input, like us, that even though the map says one zone, your area may behave like a zone that is warmer or colder than the map describes. Also, keep in mind that many gardeners think their gardening lives are harder than they really are, so take what they say with a grain of salt.

Finding the answer to the question, what is my garden zone is super important. If you gather as much info as you can about your garden and the zone/climate you live in you will have a much better idea of what to plant and when to plant it. And your garden zone is a good first step.

How Do I know my Gardening Zone?

The easiest way to learn your gardening zone is to go to the USDA website and put in your zip code.  That will give you what the map says your zone is.  Then take that information and augment it with advice from local gardening experts.

What is my Climate Zone?

Sometimes you will hear gardening zones referred to as “climate zones”.  This is just a difference in terminology and they really are talking about the same thing.

What are the growing zones in Canada?

Canadian growing zones are very similar to those in the US.  If you live in Canada you can look up your growing zone on this website.