Mowing your lawn doesn’t have to be a year-long ordeal; in fact, your grass stops growing entirely at a certain point each year!
Knowing when to schedule your last cut of the season is a bit tricky, but it’s certainly possible if you pay a bit of attention to the weather and your lawn’s growth patterns.
Grass usually stops growing sometime in fall when temperatures have dropped below 50° degrees Fahrenheit (10° C) during the day. Mowing your lawn before winter sets in or just before the first frost of the winter will help keep it healthy and prevent lawn diseases from damaging it while it is in a more sensitive state.
Read on to learn more about what time of year you should stop mowing your lawn, why it stops growing at a certain time each year, and what else you should do for your lawn during those months of stagnancy to keep it strong and healthy when it does begin growing again.
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What Time Of Year Does Grass Stop Growing?
Generally, your grass will stop growing sometime in mid-to-late fall during October or November depending on where you live. Once temperatures drop below 50° degrees Fahrenheit (10° C) during midday, this is usually low enough for the grass to quit growing until things warm back up in the spring.
All grasses are a bit different, but they all quit growing for a few months or so once the air and soil daytime temperatures drop beyond a certain point.
You might initially think the grass will keep growing as long as it isn’t freezing (below 32° degrees Fahrenheit or 0° C) outside, but actually, most grasses need conditions to be a bit warmer for them to thrive and grow consistently.
Your lawn needs plenty of sunlight and water to grow regularly.
The temperature outside also affects the soil temperature and how quickly and efficiently your lawn takes in the nutrients it needs to grow.
Interestingly, plants tend to “know” to anticipate certain seasonal changes and respond to them accordingly.
For instance, your lawn grows a lot faster during the spring and summer months because it can photosynthesize more quickly due to the consistently warmer, sunnier conditions.
Your grass also speeds up this process to prepare itself for the harsher winter months where it won’t be able to grow as much or, depending on your location, at all.
The exact time your lawn quits growing entirely also depends on whether it is warm- or cool-season grass.
While warm-season grasses are far less tolerant of significant temperature fluctuations, cool-season grasses can thrive in temperatures as low as the mid-40s, eventually ceasing their growth completely once things start to freeze over.
Usually, but not always, this occurs as the fall season begins to draw to a close for each type of grass.
What Temperature Does Grass Stop Growing?
Cool-season grasses tend to slow their growth rate at around 50° degrees Fahrenheit (10° C) and below, eventually quitting growing entirely as temperatures get closer to 32° degrees Fahrenheit (0°C). Warm-season grasses are a lot less tolerant of cold temperatures, as they generally thrive between temperatures of 70 and 90° degrees Fahrenheit (32° C).
It’s important to also note temperatures must be consistently low for an extended period for grass to quit growing completely, regardless of what season it typically thrives in.
For example, a single unseasonably chilly day at around 60° degrees Fahrenheit (16° C) in August generally isn’t enough for your lawn to close up shop for the year entirely, even if it’s a warm-season grass unless it’s already damaged and/or suffering from some kind of lawn disease.
This is why most grasses don’t stop growing altogether until mid-to-late fall, usually in October or November, as we covered earlier.
While your lawn certainly can quickly bounce back after a couple of chilly days or even a particularly cool week or two, it struggles much more to cope with long periods of cold weather and precipitation like snow and hail.
The longer the cold period lasts, the longer your lawn will take to resume its typical spring and summer growth.
As the air temperature drops, the soil temperature begins dropping with it, sending signals to the grass to slow down the rate at which it photosynthesizes and takes in nutrients.
Your lawn will also likely take on a more dull, yellowed appearance, but don’t panic–this is merely a sign of a temporary period of dormancy, not the total destruction of your lawn forever.
When Should You Stop Mowing The Lawn In The Fall?
As a general rule of thumb, if your lawn’s still growing, you should still be mowing. Keep an eye on weather patterns and mow your yard for the last time once temperatures become consistently cool, or below 50° degrees Fahrenheit (10° C) or so, usually sometime in mid-October to early December depending on where you live.
The last mow of the season varies significantly depending on your location and the weather pattern in a particular year.
Still, it should generally fall sometime in mid-to-late fall or very early winter.
Once fall begins and things start cooling down, it’s a good idea to start scaling back your usual mowing routine a bit.
Keep your grass at around 2.5” inches tall and trim around ⅓ of its total length every time you mow.
This will gradually shorten its length little by little as the grass’ overall growth rate slows down.
By doing this, you’ll begin preparing your lawn for the colder months ahead by keeping it thick, strong, and healthy.
Aerating your lawn once or twice sometime in early fall will also help increase airflow as the ground and soil become more firm and compact when winter rolls in.
Keep up with watering your lawn, but avoid overwatering, as this will just leave the grass prone to more damage later.
When it gets a bit cooler, and time for your final mow, however, you’ll need to keep your lawn a bit shorter than usual.
1.5 to 2” inches tall tends to be best for most cool-season and warm-season grasses.
Once growth has slowed to where it is almost nonexistent, you’ll know it’s time for the final mow until spring hits the following year.
This brings us to the next question you probably have–how short is too short, and what sort of pros and cons are associated with keeping your lawn short versus long during the winter?
Is It Best To Leave The Lawn Long Or Short For The Winter?
It’s best to keep your lawn about 1.5” to 2” inches tall during the winter to prevent it from sustaining too much damage from the cold. If it’s too long, it becomes heavy, matted, and damaged from the cold, but if it’s too short, it won’t grow back properly in the spring.
Keeping your lawn short for the winter protects it from frost, snow, ice, and the cold air and soil temperature in general.
The cooler months are often quite damaging to most grasses if left too long, as the overgrown blades tend to become very heavy and limp.
The resulting shade from the drooping, heavy grass also slows down surrounding plant growth, even for plants that normally fare well enough in the winter.
Heavy, dense, cold, wet grass is also uniquely prone to various lawn diseases and damaging fungi.
Keeping your lawn short will keep the individual blades of grass a lot stronger and more rigid so they don’t get weighed down and, in turn, are more resistant to these lawn diseases.
However, there is a “sweet spot” you should aim to keep your lawn at once temperatures start to drop for the winter.
For most grasses, somewhere between 1.5 and 2” inches is ideal.
If you cut your lawn too short and it cannot photosynthesize and bring in enough nutrients, it won’t be able to grow back in the spring to its usual lush, green state.
Very short, thin, weak grasses are also more easily damaged by cold conditions than longer, thicker grasses (to an extent).
Cutting your grass too short puts significant stress on the individual blades on top of the usual stress from winter, ultimately leaving it unable to bounce back normally when things finally warm up.
For best results, trim your grass gradually, taking off a bit more of its length with each mow up until your final mow of the season, where it should then be just under 2” inches or so but no shorter than 1.5” inches on average.
Learn once and for all if frequent mowing thickens grass in our article at the link.
What Months Does Grass Grow The Most?
Most grasses grow best in sunny conditions with temperatures consistently over 50° degrees Fahrenheit (10° C). This is typical during the months of late spring and early summer, though the exact growth rate will vary depending on your location and its unique weather patterns.
On average, though, most locations tend to see the most grass growth during March and June.
This is when temperatures are warm but not terribly hot, and there is usually plenty of rain to keep the grass hydrated and healthy.
The soil temperature is also at its best during this time, being moist and aerated enough to allow the grass to access all the nutrients, water, and sunlight needed to thrive from root to tip.
Keep in mind, though, very hot temperatures are often just as damaging to your lawn as the harsh cold of the winter months.
During the hottest months of July and August, conditions tend to become drier due to the intense heat.
As a result, the combined heat and dryness amplify each other’s damage.
The increased temperatures cause the grass blades to dry out at their tips.
In contrast, the dry conditions end up sapping the moisture from the soil, so the yellowing, damaged grass cannot draw up any additional moisture and nutrients to salvage itself.
Increased watering during this time is often necessary to combat occasional dry spells made worse by prolonged, intense heat.
In the early fall, most grasses experience a brief period of increased growth.
This also varies depending on your location and the particular weather patterns in your area.
Still, generally, September and October usually allow the heat-damaged grass to bounce back a bit temporarily just before temperatures start dropping off again for the winter.
For more mowing questions, check out our article on how early to mow the lawn.
Other Winter Lawn Maintenance Tips
After your last mow of the season, keep up with aerating and fertilizing your lawn. Additionally, keep your yard clean and free of debris and excess foot traffic while it is dormant in the winter, and keep a close watch on the weather patterns to anticipate when to start mowing again in the spring.
Just because your lawn is dormant during the winter doesn’t mean it doesn’t need any sort of maintenance whatsoever!
You should do a few things to protect your grass from the elements and ensure it grows back normally when things warm back up.
Aeration is one of the most important parts of having a healthy yard in the winter.
The colder temperatures cause the soil to become more densely compacted than usual, which causes the grass to be less efficient at pulling in nutrients and water.
Even simple spike aeration will go a long way in keeping the soil from becoming too solid.
Another important measure you should take in the fall and winter is to keep as much debris and traffic off your yard as possible.
Since the grass and soil are so fragile during this time, any amount of additional stress will damage it even further.
Remove any unnecessary lawn furniture and keep your pets, kids, and guests off the lawn whenever possible for best results in the springtime.
Finally, check the weather weekly, if not daily. Keeping an eye on the weather patterns in your area will give you an idea of when you should expect things to warm back up for the spring.
This will also alert you to any unusual weather patterns, snowfall, or sudden freezes, which will bring more damage.
Certain fertilizers are great for mitigating winter damage to your lawn and preparing it for the following spring.