Hardiness zones are an important part of keeping a successful garden. They will give you an idea of what can grow by indicating the lowest temperature in your zone. As you can imagine, this can be very useful. You’ll know whether or not outdoor tomatoes, for example, will survive the frost. Learn a bit about it and as a gardener, you’ll get better at your hobby. Take a look!

What Are Hardiness Zones?

A table explaining hardiness zonesHardiness zone map separate the US into 11 different climates. This helps remove a lot of the guesswork as to what you can and can’t plant in your area. There are also areas outside of the US, such as (but not limited to) Australia, Asia, Britain, etc. 

These work quite similarly. This being said, some places in the world are much warmer than the US (such as India and Australia), and their hardiness scale goes a bit higher.

Why Do Growing Zones Matter?

When it comes to picking what you grow, your hardiness zone is very important. This will let you know what plants can actually survive outside, based on the climate. It’s especially helpful for perennial plants, because annual plants die by the end of the year. Perennial plants need to survive the coldest part of the winter and the hottest part of the summer! Planting zones help you determine what plants will be able to thrive in your location’s temperature and weather.

The Hardiness Zones (A Bit About Them)

According to the USDA, the US and Canada are divided into 13 distincts, each corresponding to a certain climate. If you live somewhere else in the world and would like to know your specific USDA zones, you can look them up online. The information can help make gardening go more smoothly than ever!

The 13 US zones are 1-13, with 1 being the coldest, a minimum of -60°F, and 13 being the hottest, a minimum of 60-70°F. They are primarily based upon the coldest temperature in the winter and vary from each other roughly 10°F.

While some might think it’s as simple as your Southerly or Northerly location, there are actually many other factors that can affect your specific climate. These include lakes and mountains, and even cities and suburbs can potentially have some effect. This means that it’s always good to give your hardiness zone a double-check.

Common Plants for Each Hardiness Zone (To Get You Started)

Common plants for each growing zone

Not sure what to grow based on your climate? Here’s a good place to start.

Hardiness Zones 1-2:

Hardiness zone 1 encompasses extreme temperatures as low as -60°F. Not everything can grow in such harsh conditions, but they do exist. Here are a few of the most popular:

  • Lily of the Valley
  • Columbine
  • Cranesbill
  • Delphinium
  • Arugula
  • Kale
  • Swiss Chard
  • Creeping Jenny
  • Siberian Iris
  • Yarrow
  • Sprouting Broccoli

Hardiness Zones 3-4:

Planting zone 3 reaches lows of -30 to -40°F, calling for tough plants that can handle chilly weather!

  • Bee-Balm
  • Apples
  • Black-Eyed Susans
  • Bleeding Hearts
  • Beets
  • Blueberries
  • Carrots
  • Celery
  • Broccoli

Hardiness Zones 5-6: 

  • Beans
  • Tomatoes
  • Carrots
  • Onions
  • Cauliflower 
  • Broccoli

Hardiness Zones 7-8:

Zone 7 is still a bit limited, due to cool weather! This calls for hardy plants, such as:

  • Beets 
  • Cabbages 
  • Peas
  • Potatoes 
  • Broccoli
  • Apples
  • Bee-Balm 
  • Basil

Hardiness Zones 9-10:

Based on USDA, agricultural zone 9 is comfortably warm and allows for all kinds of plants. It has a minimum temperature of roughly 20-30°F. This allows for some more warmth-loving plants, including those below.

  • Air Plants
  • Amaryllis
  • Artichokes
  • Asparagus
  • Tomatoes
  • Zucchini

Hardiness Zones 11-12:

It’s a toasty area, with a minimum of 40-50°F. There is very little potential for freezing weather. This means that tropical-loving plants like these can successfully grow:

  • Bird of Paradise
  • Cantaloupes
  • Bell Peppers
  • Artichokes
  • Christmas Cactus
  • Coleus
  • Elephant Ear
  • Impatiens
  • Inch Plants

Hardiness Zone 13:

Finally, we’ve got hardiness area 13. This is the warmest climate in the US and can grow plants that enjoy a lot of heat, such as those below:

  • African Breadfruit
  • Amazon Tree-Grape
  • Bush Beans
  • Rosemary
  • Bananas
  • Bamboo
  • Orchids

Can You Grow Plants in the Incorrect Planting Zone?

Indoor Plants

With indoor plants, the hardiness area does not matter nearly as much. You can get away with growing all kinds of out-of-season (and out-of-climate) plants indoors (such as an orange tree). In some instances, it may take a bit of extra work, however. 

If you have a humidity-loving green baby in a dry climate, you may need to employ a humidifier or place it in a bathroom where people frequently shower. A water and pebble tray can also do the trick.

Outdoor Plants

With outdoor gardening, your growing zone is a guideline. Some outdoor plants can still survive in the incorrect climate, as long as you take certain precautions during extreme temperatures or weather. For instance, a frost cover. Or, you can simply take your outdoor plants indoors before an approaching frost. Just make sure to transition them indoors gradually, so that the plants can acclimate. Otherwise, they will go into shock.

So, there you have it: some of the primary gardening zones and what can be planted in them. You can also grow greenery elsewhere if you take protective measures against frost during the coldest part of the year. Best of luck!