As the temperatures plummet, your lawn will get ready to go into hibernation, and once that happens, there will be little scope and requirement for care. But, what you do for your lawn before the freeze hits, including the last lawn cut before winter, will determine the performance of your grass when spring comes visiting.
Mow too soon and the growth that ensues will create a rife environment for the dreaded mold and moss. Mow too late and you will be stressing grass that is already dormant. Then, there is the big question about how adventurous you ought to be getting with that lawnmower.
There are those who believe that their lawn warrants a crew cut before it retires for winter. Some others feel that a bit of length will give the turf a head start when the freeze begins to thaw.
Simply put, there are a lot of conflicting views out there. So, if you are not sure about how to handle your lawn before winter-assault begins, continue reading to know everything there is to trimming the turf before the brrrrrr-season.
The last lawn cut before winter can make or break the performance of your yard in spring. If you get the height and the timing correct, you can help the plants to survive the coldest of winters and come out greener and thicker than ever before.
Why Is The Last Cut Of The Season Most Important Of All?
With that last cut in fall, you prepare the lawn not only to get through winter but also to come back kicking in spring. Any errors with the last few cuts and you could end up leaving the grass with too little food or vulnerable to mold.
So, the timing of the last cut, the height to which the blades are chopped and other pre-winter lawn care measures play a vital role in the health of your lawn in the year to come.
What Is The Right Time For The Last Mowing Of The Year?
That depends on the growing cycle of your grass. Typically, the last mow of the season will be somewhere between October and early December, after the last of the colorful autumn foliage falls to the ground. There are two ways to know when your lawn will be up for the last trim of the year:
- As temperatures dip, you will notice a significant slowdown in the growth of the grass. Once that happens, it will only be two or three mowing sessions more before you can rest the mower for winter.
- In areas with harsh winters and cool-season grasses, the first frost of winter will be the cutoff point. Check when your area is expected to get its first frost and get in 2-3 mowing sessions before you get to that date.
Having said that, for most warm-season grasses, the dormant period starts early and lasts longer. So, your last cut will be in late fall. As far as cool-season grasses are concerned, these go through two dormant phases.
So, the one in winter is short and typically starts in early December, which puts your last cut of the year somewhere at the end of November. But, if there are sudden warm spells in late fall and early winter, these may bring your turf out of hibernation, long enough for it to warrant another mowing.
To cut a long story short, you’ll be mowing till it’s growing or till it starts snowing!
How Short Should You Go With Grass When Cutting It For The Last Time?
Just because you are mowing less frequently and will stop soon, does not mean that you should forget all about good grass trimming practices. In fact, this is one of the reasons why you need to keep an eye on the growth of the grasses or on the first frost of winter.
Over the last 2-3 cuts, you will have to trim the height gradually, setting the blades lower by inch each time. The idea is to never take off more than 1/3rd of the height that you are starting at. Now, there are a lot of people out there who claim that shorter is better for winter.
However, you should never go below the minimum safe height for your grass type. Give your lawn a crew cut, and you may stress it to the point of killing it. So, if you don’t want to be greeted by bare patches in spring, don’t get too adventurous with the mower.
That said, this is the ideal winter height that you should be going for with various grass types:
1. Cool Season Grasses
Winter-hardy turfs will thrive for a bit even when the mercury levels spiral, which means you can expect the blades to grow by an inch or more even after the last trim. So, if you work your way to the lowest end of the height range, you won’t have to worry about an overgrown turf in winter.
- Kentucky Bluegrass: 2 to 3.5 inches
- Tall fescue: 2 to 3.5 inches
- Fine fescue: 2.5 inches to un-mowed
- Perennial ryegrass: 1.5 to 2.5 inches
2. Warm Season Grasses
These take a tighter cut and it is rare to see them sprouting unexpected growth in the dead of winter even if the temperatures rise for a few days. Yet, as with the cool-season grasses, go for the shortest safe height.
- Bermuda grass: 1.5 to 3 inches
- Zoysia: 1 to 2.5 inches
- St. Augustine: 2.5 to 4 inches
- Centipede grass: 1.5 to 2 inches
What Happens If You Cut Turf Shorter Than Recommended?
Both warm and cool-season kinds of grass, store food (carbohydrates) to get through the dormant phase. This food is stored in the crown of the grass plant which is the part just above the ground.
Cutting the blades too short shocks the plants and makes the crown vulnerable to freezing temperatures, not to mention that a close crop may actually end up damaging the crown.
Also, a very short trim can cause a freeze burn when the temperature gets close to or goes below freezing. This can permanently damage the exposed plants.
Even if you have a few days to go before freezing temperatures come knocking, very short grass blades have trouble absorbing the required amount of sunlight. So, they offer weeds the opportunity to hog up the sunlight and grow unabated.
Moreover, a close shave for the turf can stunt the development of the root system of new plants. And if all of that is not enough, going shorter than 2-2.5 inches will drive the plant to dip into their winter reserve of nutrients to regain the lost height.
Why You Should Not Keep Grass Blades Longer Than Recommended?
Leave those grass blades longer than 3 inches and when snow hits, they will buckle under the weight and will get matted to the ground or to the other blades. In both cases, airflow around the blades gets disrupted.
The lack of air, and the moisture supplied by snow create a rife environment for fungal growth.
So, if you don’t mow as much as required and when required, come spring, there is a good chance that you will be greeted by the notorious pinkish-gray snow mold instead of the lush greenery that you expect.
Is It OK To Cut Grass In The Winter?
As long as the turf isn’t blanketed in snow or frost, it is safe to mow it.
But, once the grass blades are covered in frost keep off the yard or you risk breaking and crushing the frozen blade. In fact, your humble lawn mower will do the same damage to the turf as a cement roller if you try working on the yard while the grass is under ice/frost.
That said, even in fall, ensure that you don’t mow in wet conditions.
The soaked grass blades and the wet soil will make mowing a messy affair. To add to the problem, the mower will easily gouge out the grass plants by their roots if the mud wet.
To Water Or Not To Water Is The Question: Does Dormant Grass Need Water?
Yes, the plant is hibernating but the roots are still awake and they need moisture to stay alive. So, don’t give in to the common misconception that your yard can survive without watering in winter.
Having said that, melting snow towards the end of winter will provide some water; ditto for winter rain. Nonetheless, you will have to maintain a winter watering regimen, and this is how you should go about it:
- Reduce the frequency of watering to your summer routine.
- One half-inch of water per week is usually enough to sustain dormant grass.
- If the blades are still growing, you will have to provide a bit more, about an inch/week.
- Water the plants in the morning and not in the evening. This gives the roots enough time to soak up the moisture and the blades are not left drenched and susceptible to a fungal attack.
- If a snowstorm or a cold wave is expected, water the grass two days before the freeze hits. The moisture will protect the plants from frost damage and will help the blades to retain heat.
Will Aerating Your Lawn Help It Through Winter?
Fall aeration can do wonders for the health of cool-season turf. In winter, the plunging temperatures, reduce the ability of the soil to retain water. Add soil compaction and a thick thatch to this and you have the recipe for a damaged lawn in spring.
By aerating the soil in autumn, you basically open it up to absorb the nutrients you intend to supply to it. Plus, aeration opens up the root zones, enabling better and more robust root system development. So, your grass comes back stronger, lusher, and greener.
But, it is crucial to aerate the soil when the turf is actively growing, which means that winter aeration, once the grass has gone dormant, is a strict, “NO-NO”. If you aerate early in fall, this will give you enough time to combine aeration with overseeding and winterizer application.
However, if you are dealing with soil compaction or flooding issues you can aerate up until the end of November and your lawn will only suffer minimal damage, but the results can be good if you are dealing with very significant soil compaction.
What Is The Best Lawn Fertilizer For Winter?
A nitrogen-rich fertilizer is the bests for winterization of the cool-season turf. There are some homeowners and lawn care services that continue to use potassium and phosphorous rich products with negligible amount of nitrogen.
But research has proved that nitrogen can do your greens a world of good. Nitrogen increases chlorophyll, which has a direct impact on photosynthesis.
More photosynthesis means more sugars are made by the plant. Since the leaves aren’t growing, these sugars get saved for winter survival and recovery in spring.
Because these sugars are stored in the plant cells, they make the individual blades, and the plant itself more resilient to temperature plunges in winter.
Also, nitrogen application in winter promotes more prolific and deeper root growth. So, the turf walks into spring with healthier roots.
Plus, the stored nitrogen in the roots is available when the plants need it in spring. So, winter fertilizer application also helps to bring spring-green up early.
Warm-season lawns should not be fertilized in winter, and certainly not with a nitrogen-rich product. You may want to consider the use of a potassium-based product (K₂0- Potash). But, apply it in winter only if soil tests show a paucity of potassium.
When should you apply winter fertilizer?
The fertilizer can be applied in one or two sessions. If you are only going for one application, mid-autumn, around mid to end of October, would be a good time for it.
Go for 1 pound nitrogen/1000 sq. ft. if you had good growth and 2 pound nitrogen/1000 sq. ft. if the growth was weak.
For two sessions, this is what you should do:
1. The first application should be in early fall or even at the very end of summer. Your lawn will need to pound of nitrogen for each 1000 sq.ft.
2. The second application should be when the growth has slowed down considerably. For this application, you will have to provide 1 pound nitrogen/1000 sq. ft.
The thing about fall/winter fertilizer application is that it is not meant to boost immediate turf performance. You are simply supplying the food that the plant will need to tide over winter and grow back in spring.
So, if you fertilize too early, you fueling succulent growth and if you hold it off for too long, the fertilizer will not get enough time to penetrate the soil layers and make it to the plant roots.
Best Winter Fertilizer Numbers
The three numbers simply indicate the ratio of the 3 major nutrients in the fertilizer that the turf needs for general health.
- The first number always stands for the amount of nitrogen (N).
- The second is for phosphorous (P).
- And the third stands for potassium (K).
Sometimes, you will see a 4th number, which stands for all other trace minerals/micronutrients such as zinc, iron and other.
So a number like 15-15-15, means that all 3 minerals are added in equal amounts; i.e. 15% each. Along the same lines, a number such as 15-5-10, indicates that the product has 15% nitrogen, 5% phosphorous and 10% potassium.
For a two-stage fertilizer application, opt for a nitrogen-rich product such as 20-8-8 in early fall and go for a phosphorous rich product such as 13-25-12 in late fall, which will boost root growth.
For a single application in mid-fall, choose a nitrogen loaded fertilizer like 21-7-14.
If you can only wriggle in one fertilizer application and that too in early winter, go for 20-8-8.
When Should You Put Down Winter Fertilizer?
At the latest, you should fertilize for winter when the grass stops growing but is still green on top, which indicates root activity below.
Once the temperatures plunge below 50 degrees and the growth stops completely, it is time to put your mower away. And that is also when you put away the bag of fertilizer.
There you have it folks, everything that you need to know about the last turf trim of the year, and how to give your lawn all the TLC it will need to get through those freezing winter months.
When it comes to lush lawns, the one fact to accept is that the gorgeous greenery does not spurt out on its own.
Impressive turfs call for meticulous planning and diligent hard work.
So, if you want your lawn to be the talk of the neighborhood, you will need to devise a season-specific plan and stick to it. If all is done as it should be, there is no reason why you won’t have the most ogle-worthy lawn on the block!