Have you heard of the term planting zone? Are you uncertain of what it means?
When I first began gardening years ago, I hadn’t heard of this term. I started to note it as I was scrolling through the internet trying to learn how to grow specific plants.
I’d also see it mentioned on plant packaging at local nurseries, but I had no idea what it meant or how it pertained to me.
If you’re feeling like this, you’re in the right place. I’m going to walk you through what a planting zone is, what it isn’t, how to understand the hardiness zone map, and much more.
Let’s get started!
What is a Planting Zone?
Planting zones are illustrated on a map known as the USDA Hardiness Zone Map. It’s divided out in areas which range from planting zone 1A to planting zone 13B. These are areas which range in minimum temperatures from -60 degrees Fahrenheit to 70 degrees Fahrenheit.
This system was designed for the gardening and agricultural industry. It was a way for companies to demonstrate which plants would work best in which areas, based on climate. It is important information for professional landscapers, as well as farmers.
However, it carried over to backyard gardeners and made it much easier to figure out which plants work best in each’s garden.
The idea is to match up plants and the climates where they originated from, with other similar environments around the map. By understanding what zone you’re located in, allows you to know which plants will grow best in your area and which won’t.
Also, which perennials will work as true perennials, and which will have to be treated as annuals. Knowing which planting zone you are located in can impact your gardening success in tremendous ways.
What a Planting Zone is Not
It’s common for people to look at the Hardiness Zone Map and assume it would be divided out by region. We commonly perceive certain states as sharing similar climate conditions.
This isn’t reality. I’ll share more with you in the next section how the USDA Hardiness Zone Map is determined.
For now, understand you can’t decide which plant should be planted in your area based solely on the region you live.
It’s more accurate to use planting zones because it’s measured by the climate which can be different in areas in proximity to each other.
How to Use the USDA Hardiness Zone Map
The USDA Hardiness Zone Map is created by collecting data from news stations around the United States.
Once the data is in, the process starts with determining the average minimum temperature per area. Based on these averages different zones have been created.
1A is the coldest zone which averages a minimum temperature of -60 degrees Fahrenheit. 13B is the warmest zone which averages a minimum temperature of 70 degrees Fahrenheit.
When deciding what to plant in each zone, the plant must be able to thrive in a climate with the minimum temperature.
For instance, if I was planting in zone 9A, the plant must be able to survive a minimum temperature of 20 degrees Fahrenheit as a perennial.
However, if I wanted to plant something like an annual, I could check my frost dates and get a time frame as to when it would be safe to plant in my zone.
Using the map is simple. You can either locate the actual USDA Hardiness Zone Map and find your location on it. From there, use the color-coded key to find out in what zone you are.
Or you can use a digital tool for locating planting zones. You enter your zip code, and the planting zone will be displayed.
Why Planting Zones Matter
If you’ve ever put in the effort to start your plants from seeds, or you’ve shelled out the money to plant a garden from seedlings someone else has started, you understand why planting zones matter.
Planting a garden is an investment of both time and money. If you plant something at the wrong time for your zone, you’ve wasted time, money, and effort.
When you understand your zone, you know how large of a time window you have for growing things. Then you know how early or how late you can start growing something.
For instance, it’s common for people in parts of Alaska only to have a three-month growing season. Whereas people in zone seven through ten can produce a variety of plants practically year-round.
If you’re unsure how to determine which plant grows in what zone and when, then use a planting schedule based on your area.
This will show you what months to start seeds indoors, when to plant them outdoors, and if they can be grown in your area a second time.
You can also read the packaging at nurseries which will read “Hardy up to zone ___” or “Will grow in _____ zone and below during _______ season.”
Planting zones are the beginning of growing a successful garden.
Other Factors Which Will Impact Your Garden
Planting zones are essential to your garden, but they aren’t the know-all-end-all. There are other pieces to the gardening puzzle.
It’s important to understand each piece because knowing your zone and planting at the proper time for your zone will not equate to success without these essential elements:
1. Soil Quality
Planting in quality soil is important. You should test for soil pH and make sure it’s at the proper level for the plants in your garden.
Also, be sure to amend your soil with compost and other organic matter to help make it fluffy and well-drained.
2. Water
Everything needs water. If it doesn’t have it, it’ll die. Pretty simple to understand, right? Well, there are a few more elements to understanding how to water your garden correctly.
The rule of thumb is to give your plants one inch of water per week. Be sure to apply the water in one or two deep watering sessions per week instead of four or five shallow watering sessions throughout the week.
3. Sunlight
As everything needs water, everything needs sunlight too. Be sure your garden is in a sunny location with well-draining soil.
It’s a good idea to place your garden where it’ll get at least six hours of sunlight per day. If this isn’t feasible on your property, consider container gardening where you can move your garden around to get adequate sunlight.
4. Regional Factors
As I’ve mentioned, zones can vary in your region. Some states can have two or more zones in their state alone.
That leads to different temperatures and planting times, but they all have to face certain weather conditions common to their area.
For example, zone eight is a broad zone. It spreads from the east coast of the United States to the west coast.
What one person in zone 8 may deal with on the east coast, someone on the west coast in zone 8 may not have to deal with.
Certain areas of zone 8 are much hotter than other areas. Some locations deal with hurricanes and tornadoes, while other locations don’t experience this as much.
If you live in an area where you know you will face extremely high temperatures or drought at some point in the gardening season, you could plan ahead by creating a hugelkultur garden. Understanding what weather threats are common in your region can help you better prepare your garden.
All of these factors can be considered and planned for to give your garden the greatest chance of success.
How to Work Around Planting Zones
If you live in an area where you have a relatively small window for gardening, there are some ways to work around this. Here are your options:
1. Don’t Grow Certain Plants
There are some plants which take too long to grow in some areas. If you have a three month grow window and a plant takes over 100 days to produce, you’ve lost out.
In these cases, you may have to decide you can’t grow certain varieties of crops because of where you’re located. It can be heartbreaking to make this decision, but sometimes it isn’t worth the headache to plant something outside of your planting zone.
2. Plant Perennials as Annuals
There are some plants which won’t survive in your planting zone because the minimum temperature gets too cold.
If you love a specific plant and want it around anyway, as long as you’re willing to invest and plant a new annual year after year you can still grow it.
3. Practice Alternative Growing Methods
Your final option is practice alternative growing methods. Many people in colder locations use greenhouses to prolong their growing period.
It is a great way to start seeds earlier and produce crops later. Though I don’t live in an unusually cold zone, I use a greenhouse to grow vegetables over the winter to keep the frost off of them.
You can also practice straw bale gardening to be able to plant earlier since you build the garden and soil each year.
Well, you now know what the USDA Hardiness Zone Map is, how it’s determined, how to determine your zone, and much more.
Hopefully, this will encourage you to dive deeper into the world of gardening and embrace gardening to its fullest in your area.