Knowing and understanding the grass zone you live in is key to having a healthy lawn. Not only will it tell you what types of lawn grass will grow well in your region (and which will not), but it will also help you discover the best lawn maintenance schedule for your yard. In the grass zone map featured at the top of this article, you’ll notice that there are three primary grass growing zones in the United States.
If you don’t know which one you live in and what that means for your lawn, you’ve come to the right place.
Beyond the grass zone map featured at the top of this article, I’ll also share some details you can observe about the microclimate in your yard to guide you toward the best turfgrass for your property, and steer you toward lawn care routines and products that will work for your yard.
Let’s start by defining the three grass zones in the USA.
The Three Primary Grass Growing Zones
There are three grass growing zones in the US:
- Cool Season Grass Growing Zone,
- Warm Season Grass Growing Zone, and the
- Transition Growing Zone for Grasses.
While it may be obvious which of these three zones you live in, there’s a little more to it than that.
Let’s take a closer look at the three primary grass growing zones (as well as sub-zones/climates of note) in the United States.
Below, I will discuss defining characteristics of the grasses which thrive in each of the different zones and what it is about the growing conditions each zone offers which allows different grasses to thrive.
Further, I’ll help you identify features in your local climate, which can steer you correctly toward one type of grass over another.
The best cool season grass for Northern Kentucky may differ from the cool season grass that will survive North Dakota’s harsh winters.
You’ll want a disease-resistant warm season grass in the humidity of Florida, and one that can tolerate sustained drought conditions in the Texas hills.
Just because there are three grass growing regions on a grass zone map doesn’t mean choosing the best grass for your yard is simple.
There’s actually a lot to understand.
Cool Season Grass Zone
The cool season grass zone encompasses all the way from the Canadian border to places such as southern Kansas. This zone is known for cold winters and hot summers, and cool season grasses typically grow best during the spring and fall.
For a grass to do well in this region, they need to be adapted to flourish in places that have dramatic temperature fluctuations (for example, extremely cold winters and hot, dry summers).
Cool Season Grasses grow best when temperatures are between 60 and 75 degrees Fahrenheit. That is the reason why these grasses have most of their growth in the spring and fall.
How to Grow and Mow
While there is cool-season grass available in sod form, if you live in the cool-season grass zone, then you may be best off growing your lawn from seed.
A mowing height of between three and four inches is generally best for maintaining cool-season grasses, particularly if your lawn is predominantly tall fescue (which many cool season lawns are). Some cool season grass varieties benefit from a slightly lower mower deck setting.
Popular Cool Season Grass Types
The best known cool-season grasses are:
- Fescue (both Tall and Fine Fescue),
- Kentucky Bluegrass, and
- Perennial Ryegrass.
In many cases your best option is to buy a northern seed blend which contains all three of these grass varieties. A seed blend for your region will contain grass cultivars known to thrive in your particular part of the country, and these grass seed mixtures will contain some grasses which can handle dense shade, intense sun, or high traffic.
We all have different growing conditions in different parts of our yard. That’s why using a single type of grass seed everywhere may not be the best solution.
A quality grass seed blend will allow the dominant grass for shade, sun, wet, and dry conditions to take over where those conditions exist. Most select grass cultivars which are closely matched in color.
This will offer you a nice thick lawn throughout your yard, with consistent coloration.
The Transition Zone sits between the cool season grass zone and the warm season grass zone.
Examples of areas found in the transition zone include most of California, northern Arizona, southern Kansas, Arkansas, West Virginia, Virginia, and northern Georgia.
If you are in the transition zone, you have a combination of northern and southern weather patterns. This makes it difficult to choose the grass that would be best for your area, and (generally speaking) you may find it more difficult to grow a good lawn compared to your northern and southern neighbors.
The winter weather is too cold for warm-season grass, but it’s tricky to have cool-season grasses because of how hot the summers get in your part of the country.
When choosing a grass in the transition zone, you need to think about the characteristics and conditions of your specific area and your yard.
You will need to carefully consider the advantages and disadvantages of each type of grass.
Speak with Your Neighbors
You should also ask your neighbors (the ones with lawns you admire) what’s growing in their lawn, and how they find maintenance of that grass type to be.
Just because the retiree down the street who is taking care of his grass every day has a good lawn … that doesn’t mean that grass type will work well for you and your schedule.
The specific conditions of your area (and your willingness to maintain your grass) will determine whether a warm-season or cool-season grass will be best for your lawn in the transitional zone.
My Recommendations for Transition Zone Grass Varieties
Many types of grass seeds are available in blends and combinations, but for many people tall fescue is a good choice. This is because of all the cool season grasses, tall fescue grows some of the deepest roots.
Combine its cold tolerance, winter hardiness, and deep roots that will help it survive your hot summers, and it’s a popular choice for transition zone lawns on the northern end of the spectrum.
For transition zone lawns that skew southern, I recommend looking into Zoysia – either sod or plugs (because Zoysia grass spreads slowly).
Zoysia is one of my favorite lawn varieties – it’s truly beautiful.
Things to Consider
Think about the pros and cons of growing a cool-season grass or warm-season grass in your area. Consider which features are most important to you and the downsides that you are willing to put up with.
Also consider what kinds of extra maintenance you are willing (or not willing) to do to get optimal performance out of your lawn.
If you’ve tried everything and haven’t had much success, you could always choose a grass lawn alternative.
Warm Season Grass Zone
The warm season grass zone sits to the south of the transition zone. It includes the southern states and regions of the United States, and grasses that thrive here look and grow differently than many northern lawn grasses.
This region has moisture levels that range from humid to arid, which means that a warm season grass that grows well in Florida, may not work for your home in southern Oklahoma.
The temperatures at which warm season grasses grow most optimally are between 26 and 35 Celsius (~79-95 Fahrenheit).
If you’re growing a warm season grass from seed, shoots will start appearing when the temperature of the soil gets higher than 15 Celsius (60 degrees Fahrenheit). But your lawn won’t really take off until it gets much warmer.
Adapting to Handle Drought
Warm season grasses have differences from their northern cousins in terms of photosynthesis. These southern grasses are classified as C4 plants instead of C3 plants.
This classification comes from their use of the four carbon compound PEP Carboxylase (C4 for four-carbon). In essence, this describes the ability of warm season grasses to gather carbon dioxide in a more efficient manner than C3 plants, which allows them to keep their stomates closed. This, in turn, allows warm season grasses to deal with extreme heat and drought for prolonged periods.
This is a crucial characteristic when it comes to the southern states, as the summers are so extremely hot and the average temperature is higher all year.
Popular examples of warm season grasses are:
- Centipede Grass,
- Zoysia Grass,
- St. Augustine Grass, and
Sub-Zones/Climates in the United States
While there are only three primary grass zones in the United States, there are many sub-zones and climates within those zones.
While most Grass Zone Maps don’t acknowledge these growing zones, it’s worth mentioning them and explaining a bit about them.
The cool/humid and cool/arid sub-zones are parts of the cool-grass zone.
The cool/humid zone includes not only the Northeast but also some of the Midwestern states and a great deal of the Pacific Northwest.
You can grow any and all of the cool-season grass varieties in this region. Certain kinds of warm season grasses (such as Buffalo Grass) can be grown here but only in areas that have lower humidity levels.
The cool/arid sub-region encompasses many of the dryer regions of the Midwest and of the West.
In this sub-zone you will have the most success with cool season grasses if you have good irrigation availability.
It’s becoming quite common to use Buffalo grass in warmer parts of this sub-region, such as Colorado, Nebraska, and Kansas. In southern and western parts of this sub-zone, Zoysia grass is also sometimes used.
The warm/humid sub-zone is part of the warm-grass zone.
This is a sub-zone of the warm weather grass zone. The warm/humid sub-zone includes the Gulf states and the Southeast.
You will have success with warm season grasses if you live in this part of the country. One of the most common grasses used here is Zoysia grass. While Bermudagrass is also used here, you have to be careful with this in the northern areas as it will often suffer damage over the winter.
If you live in the Gulf Coast states, Bahia Grass, Carpetgrass, Centipede Grass, Seashore Paspalum, and St. Augustine grass are also popular.
Understand Your Grass Zone If You Want a Beautiful Lawn
Having the most beautiful lawn in the neighborhood is impossible if you don’t understand your grass zone.
With the help of my grass zone map and the short description of the conditions that can determine which type of grass may be best for your lawn, hopefully you can take the next steps in your lawn renovation.
Whether you’re looking to plant a new lawn from scratch, lay sod, or plan to aerate, overseed, and top-dress to level your yard, you can choose the best grass seed for your property.