It happens every year: one day you notice you no longer need to bust out the mower to give it a trim. Instead, it’s time to dig out the rake and garbage bags to clear away fallen leaves. But you may still be wondering, “When does grass stop growing….and how does that happen?”
Grass stops growing for a variety of reasons, such as lack of light, heat, water, proper nutrients in the soil, and extreme soil temperatures.Kyle @ The Backyard Master
Typically the grass in your lawn will stop growing when the temperature drops and remains steadily below 50 degrees Fahrenheit. For most of us in the U.S. that’s toward the end of summer and the beginning of fall.
Read on to learn what is happening beneath the surface during this time of year that impacts that growth cycle of your grass.
What Makes the Grass Stop Growing?
To the casual observer, it might seem as if the ground freezes over, killing the grass, and when it warms up again, the sun and rain cause new grass to grow.
However, that’s not what really goes down. Before discussing what actually happens to the grass, let’s take a moment to review of the reasons it stops growing.
Extreme Soil Temperatures
It may be surprising that the temperature in the air is less of a factor than the temperature of the soil. There can be quite a difference between the ambient temperature of the air and the measured temp of the soil.
Soil temperature is more important because if the soil gets too cold, the ground will freeze, creating a barrier against natural water irrigation….which as you probably guessed is not good.
On the other hand, if the soil gets too hot, the water available to grass roots will evaporate, causing the grass to wither…also not good.
What Temperature Does Grass Go Dormant?
As a general rule, grass will stop growing when the soil temps fall below 55 degrees or rise above 90.
Other factors involved in the ceasing of growth include:
- Lack of light- During the winter, when the days are shorter, grass receives less than the exposure necessary for growth.
- Lack of Heat – When the soil is properly heated, it has more energy to facilitate the chemical process involved in making the grass grow.
- Lack of Water – When a plant, in this case grass, lacks water, it is the same as when humans lack food. No energy for growth is produced. Although unlike humans, who die without food, grass will simply become dormant until conditions improve, and the roots can receive everything which is necessary for growth.
- Lack of Nutrients – These function like vitamins for grass. For example, chlorine assists with photosynthesis, and iron contributes to its rich green hue. For information on additional nutrients, visit: Penn State Extension
Now that we have looked at the specific reasons the grass stops growing, the next question becomes:
Is Your Grass Dead or Dormant? How to Tell
Although it is possible for grass to die and never come back, this is not what actually occurs during the fall and winter months. That is, of course, assuming the lawn has been properly cared for, and there have not been any disruptions such as a major summer drought.
What does happen is the grass goes dormant, a state in which it uses fewer of the resources needed for survival.
However, proper care of the lawn means checking to make sure the grass is, in fact, dormant, as opposed to dead.
Does Brown Grass Mean Dead Grass?
If the grass is brown all over, it is likely just dormant. On the other hand, if it is mostly green with patches of brown, then those parts may be dead.
One way to determine whether your grass is dead or simply dormant is to pull up a handful. If it comes up easily, it’s dead. Awwwwe…poor grass.
How Long Does Grass Stay Dormant?
Well, depending on why it’s dormant, the length of dormancy can differ. However, in most cases, it can stay in a dormant stage for up to 4 weeks before becoming a lost cause.
Grass comes out of dormancy from the roots-upward, so it may take a few weeks for you to start seeing signs of life.
So, if you’ve tugged on your browning grass and the roots are still holding strong, odds are your grass is dormant.
So, what can you do in the meantime to keep that grass healthy and avoid letting it die?
How to Take Care of Dormant Grass
In most cases, dormant grass can come back on its own.
However, it is in the best interest of the lawn for you to perform some proactive care in order to optimize its revival and long-term health.
Here is a list of these relatively simple but important tasks:
Let in The Light, Water, and Air
The main idea behind caring for grass that has stopped growing is making sure what it needs to survive is readily available. Your grass needs ample sunshine, water and air.
So here’s what you can do to make sure your grass survives dormancy.
- Clear away slush, sticks, leaves, and any other debris.
- Remove the thatch from between the soil and grass.
- Let the soil breathe by aerating it.
What about scenarios that are outside the seasonal cycles? What if disaster should strike, such as pests, drought, or disease, and your lawn starts dying? You need to determine how widespread the problem is and then provide the solution – reseeding your lawn.
How to Revive Dead Grass
If you’ve got dry, brown patches of grass and you’re not sure whether it’s dead-dead or just dormant, the important thing is to act quickly. You don’t want those patches to spread. Here are the steps to addressing the issue:
Identify the Problem Areas
Mark the areas on your lawn that need fixing. If you have several small patches close together, consider them one area:
- Clean up the area. Remove any weeds and rocks. If the area has been overwatered, allow it to dry out first.
- Mark the area. Add a 4-inch margin around the perimeter. You can do this with small stakes and strings.
- Make it visible. Tie something bright on each piece of string to make the area stand out to anyone else who may use or work in your yard.
Prepare the Area and Plant New Grass Seed
Now, you’ll need to dig out the dead grass and get the soil ready for new seed:
- Dig. Go down about 6 inches, breaking up the soil as you go and mixing in compost or manure to make the soil rich and ready for seeds.
- Scatter the seeds. You can use a soil spreader or spread with your hands. The area should be well covered.
- If you suspect a fungus or insects had a hand in your grass issue: Now is the time to apply an insecticide or fungicide, along with the seeds. Most are designed to work in tandem with the grass seed and will not harm it.
- Rake and cover. Gently rake in the seeds, then cover with a fine layer of sphagnum peat moss and, if possible, straw.
This final layer will hold the seeds down, protect them from snacking birds, and retain the moisture. This will allow them to germinate without outside disruption and develop strong roots.
Water Well and Often
Now that your seeds are securely set, you’ll need to make sure they get enough water. And not too much at once – you don’t want to wash them away or drown them.
- Saturate with the sprayer. So as not to waterlog the seeds, cover them with a steady spray of water from the hose. You want to saturate well on this first watering.
- Follow up daily. Monitor how wet the area is and saturate regularly, depending on the weather. If it rains, you’re in luck! If it’s 90-degrees and sunny, water more often.
Once the grass has grown tall enough that you have to mow it, you can remove the straw or moss, or you can just let it get chopped up when you mow, and it will decompose into the soil.
Learn more here:
Grass growth slows down or stops for a limited number of reasons. If you live in areas with extreme temperatures this can be a completely normal and expected process that will take place every year. It’s also important to remember that depending on environmental and weather conditions, the grass is either dormant or dead. If it’s dormant your job is just to care for it until it starts to grow again. If your grass has gotten too stressed and died the good news is that, most lawns can be repaired or reseeded to restore a healthy, green lawn.