How can you tell if your grass is dead or dormant? It’s not always so easy for the average homeowner. Grass typically goes dormant when it’s experiencing heat and drought stress or cold temperatures and happens uniformly across your lawn. Dead grass happens for a myriad of reasons and typically appears as circles or errant patches across the yard.
So, let’s examine your brown grass more closely. Is it really dead? Or is it just dormant?
Is my grass dead or dormant?
Seeing the green of your lawn replaced by brown is enough to strike fear in any homeowner. No one wants to see their hard work and dedication wither away. But before you rip up the grass and lay new sod or overseed, take a minute to determine if your grass is dead or simply dormant.
Consider the weather
First and foremost it’s critical to think about whether or not the environmental conditions are conducive for triggering dormancy. We talk a bit more in-depth about what causes grass to go dormant, but in simple terms, grass goes dormant as a self-defense mechanism when it’s stressed.
When it comes to weather, consider the following:
- Are you experiencing peak summertime temperatures? Or abnormally hot conditions for your area?
- Are you going into fall and temperatures are dropping lower for the season?
- Are you experiencing drought conditions?
Look at its appearance
When asking yourself, “Is my grass dead or dormant?” the first step is to look at the clues it’s showing. Is the entire lawn brown? Or do you have some spots where the grass is green and places where it’s crunchy and straw-like?
When grass goes dormant, it typically turns brown evenly across the yard. Dead grass usually appears as distinct brown circles or spots, with other areas remaining vibrant green.
I say typically, though, because warm-season and cool-season grasses look different as they go in and out of dormancy.
- Warm-season grasses like St. Augustine or Bermuda, in particular, can show funky patterns when going in or out of dormancy. If your lawn is showing signs of change but there is a consistent pattern overall, then it’s a good sign the grass is still alive.
- Cool-season grasses like Kentucky bluegrass and tall fescue have a uniformly brown or yellowish shade. If the grass is dormant, there won’t be any discrepancies across your lawn.
Another thing to look at is the crown of the plants, right at the soil surface. With dormant grass the crowns will still appear green; with dead grass, the entire above-ground portion will look brown.
Kelly Kopp, Utah State University Extension water conservation and turf grass specialist, says this about turfgrass dormancy: “Dormancy is characterized by a complete cessation of growth along with brown or dead grass blades. Grass blades are less of a concern than the crown of the grass plant, which is at the soil surface and is the point from which the grass blades grow up and the roots grow down. As long as the crown remains alive, grass has the capability to recover when temperature and moisture conditions improve. By entering dormancy, grasses are protecting their crowns for future recovery.”
Tug on the blades
The simplest approach to determine if your lawn is dead or dormant is the tug test. Simply take hold of one small patch of grass and pull.
If there’s resistance and the roots look white, then your lawn is simply sleeping. But if your grass comes right up, it means the blades have disconnected from the roots, and the patch may be dead or quickly on its way there.
Give the grass some water
When was the last time you gave your lawn a good watering? If you don’t have an automatic irrigation system, manually watering your grass may help determine if it is simply dormant or has completely given up the ghost.
Water the lawn for a few days in addition to your normal watering schedule. If the grass greens up and comes back to life after a good, long drink, it was dormant and just needed more water. If the grass doesn’t revive and stays brown and unresponsive, it’s probably dead.
Run a soil test
Lastly, it’s a good idea to take a soil sample and have it professionally analyzed, looking at nutrient concentrations (nitrogen, phosphorus, and potassium) and disease-causing pathogens. A soil test report can offer helpful insight on your soil’s fertility. It can shed light on whether you have deficiencies or toxicities that are directly harming your grass or making it more susceptible to disease problems, and it can confirm if you have damaging diseases present.
Pro tip: In many cases, you can have soil testing performed by your local cooperative extension office. A cooperative extension is a program within a land-grant university that helps the community with issues related to gardening and agriculture. You can use this list of cooperative extensions nationwide to find your nearest office.
Why does grass go dormant?
Dormancy is a plant’s natural protection mechanism normally triggered by environmental stressors such as cold temperatures in the winter or hot, dry conditions during summer. It is usually triggered when temperatures drop below 45 degrees Fahrenheit for several days in a row or when they consistently sit higher than 95 degrees Fahrenheit.
These numbers are just a guideline, though. The exact temperatures triggering dormancy can vary a bit from region to region, as different climates have different periods when the grass goes dormant.
Plus, as cool-season and warm-season grasses grow differently through the season, they have different dormancy periods. Warm-season grasses are more tolerant of high temperatures and less tolerant of low temperatures. On the other hand, cool-season grasses go dormant in hot weather while tolerating colder temperatures.
Cool-season grass dormancy
If you live in the top half of the U.S., you likely have cool-season grasses.
Cool-season grasses aren’t as efficient in their use of water or nutrients as warm-season varieties, so they tend to go dormant during extended periods of drought and extreme summer heat. These species generally go dormant when the average air temperatures head north of 75 degrees Fahrenheit.
In the winter months, your cool-season grass won’t necessarily go dormant or look dead but instead, go into what is referred to as a suspended form of growth when temperatures drop below 40 degrees Fahrenheit. At these low temperatures, the grasses will create complex sugars as an antifreeze, which helps them survive frigid temperatures.
| Grass type | Stops growing below this temperature (Fahrenheit) | Stops growing above this temperature (Fahrenheit) |
| Fine fescue | 34° | 85° |
| Kentucky bluegrass | 32° | 85° |
| Perennial ryegrass | 32° | 80° |
| Tall fescue | 37° | 90° |
Warm-season grass dormancy
If you live in the bottom half of the U.S., you probably have warm-season grasses.
Even though warm-season grasses are more efficient at using water and nutrients, these species generally go dormant when the average air temperature drops below 50 to 55 degrees Fahrenheit. This time of year will vary depending on where you live and the climate. For moderate climates, this dormancy period usually begins around mid-November.
While warm-season grasses handle heat well, they can also stop growing when summer temperatures rise above 90 degrees Fahrenheit.
| Grass type | Stops growing below this temperature (Fahrenheit) | Stops growing above this temperature (Fahrenheit) |
| Bahiagrass | 50° | 86° |
| Bermudagrass | 50° | 100° |
| Buffalograss | 50° | 90° |
| Carpetgrass | 60° | 90° |
| Centipedegrass | 55° | 95° |
| St. Augustinegrass | 55° | 95° |
| Zoysiagrass | 50° | 95° |
What causes grass to die?
I’d like to say it’s easy to determine the cause behind dead patches of grass, but the list of reasons your grass may die seems never-ending. Some of the most common culprits include excessive thatch layers that limit water and nutrient movement, drought stress, bad mowing practices, improper watering, summer pests, and lawn diseases.
For help determining why your grass is dying or dead, here are some fantastic starting points:
- How to Get Rid of Grubs in Your Lawn
- Most Common Diseases in Fine Fescue Grass
- Most Common Kentucky Bluegrass Diseases
- Most Common Diseases Affecting Zoysiagrass
- Most Common Diseases in St. Augustinegrass
- 5 Common Bermudagrass Diseases
FAQs about dead or dormant grass
What temperature kills grass?
According to Turfax, the lethal threshold for grasses is based on tissue temperature rather than air temperature. Even if the air is hotter or colder than the temperatures below, your grass could survive if the grass is well insulated.
- Warm-season grasses die when tissue temperatures rise above 110 to 120 degrees Fahrenheit or drop below 31 to 20 degrees Fahrenheit.
- Cool-season grasses die when tissue temperatures rise above 104 and 112 degrees Fahrenheit or drop below 26 to -20 degrees Fahrenheit.
How do I take care of dormant grass?
When your lawn isn’t growing, it needs less attention, but it also means you need to be more careful.
- Stop mowing: Mowing your grass when it isn’t growing will only stress it out. Give you and your grass a break.
- Scale back on watering: When your grass is dormant, it still needs some moisture, albeit considerably less than when it’s actively growing. If the ground isn’t frozen, water enough to keep the top inch or two of soil moist.
- Don’t fertilize outside of the growing season: Your grass either won’t absorb it, or the fertilizer will trigger new growth that’s too vulnerable to temperature extremes and drought.
- Wait to aerate: While beneficial, aeration is an invasive procedure. The best time to aerate is when the grass is actively growing so it can recover quickly.
- Keep foot traffic low: Dormant grass won’t recover from foot traffic, and it’s easily damaged in freezing weather.
How do I fix dead patches of grass?
The first step in bringing grass back to life is determining the problem and fixing the underlying issue. Once that is taken care of, you can either overseed the dead patches or lay new sod.
When choosing whether to overseed or sod, you have to look at different factors such as budget, how much work you want to do, and how quickly you want a new lawn.
- Sod costs around $0.31 to $0.82 per square foot nationwide. If you hire a professional, the price will be between $0.86 and $1.75 per square foot installed. It’s the more expensive option, but you’ll have established grass quicker.
- On average, the cost to seed a lawn is between $0.09 and $0.19 per square foot or around $592 to $1,768. It’s the cheaper option, but takes much longer to see results.
Need help with your lawn?
Your grass is an important part of your home’s aesthetic, and you work hard with watering, weed control, fertilization, and mowing to maintain a lush, green carpet. It’s not an easy part of being a homeowner but the dedication is worthwhile when you can stroll across a beautiful backyard!
However, if keeping up with all the lawn care tasks on your to-do list has you stressed, it’s time to reach out to the pros. Lawn Love will put you in touch with qualified local lawn care companies dedicated to keeping your lawn looking its best!
Main Image Credit: Laura Ballard | Adobe Stock | License
