When Should You Apply a Winter Fertilizer to Grass?

When Should You Apply a Winter Fertilizer to Grass

Unless you’re a newbie to this “Lush Lawn” movement, you must have heard that Lawn Winterizing is the 3rd most important fertilizing of the year. In this post, we’re going to discuss why they’re important, how and when to winterize your lawn.

Winterizing is all about adding Nitrogen to your grass after it starts growing, just before in enter a dormancy period. And by the dormancy period, I mean during the cold winters when your grass stops growing but still absorbs energy.

Instead of using this energy to grow up, the grass channels it to the roots and could be lost even before winter’s over. But here’s where winterizing comes in. Winterizing fertilizers helps your lawn to store this food for winter survival, and healthy rapid growth in the Spring.

The Nitrogen you apply to the grass-root helps to store the energy through the Spring season, so you’ll have some early green ups and better growth rate.

Before we jump to the next part of this post, I want to make sure you understand that Winterizing won’t make your grass grow; they’re more like a survival kit for Fall, and a booster during Spring.

When Should I Fertilize The Lawn For or During the Winter

As I’ve mentioned already, the best time to winterize your lawn should be just before it starts setting into the dormancy period, i.e., when it’s almost winter. If you’ve already seen any snowfall, you may want to check your weather forecast for a week or two from now to see if you’ll have any warmth and if yes, that should be your opportunity to winterize your lawn.

Generally, winterizing is best in October or early November when the temperature is around the upper 40ish… But if you want to take full advantage, apply fertilizer to your lawn in early September.

If you’re already out of luck for winterizing, and the weather forecast has left you no hope of warmth till Spring, then you might have to wait till Spring, and kick off early with fertilizing. And don’t go too heavy on the lawn if you fertilize earlier during Spring. Because spring grass already grows on its own, so you might end up mowing every day, and it becomes a pain there.

FYI – If you have a lawn and don’t know how to make it look it’s best then take a look here for my free “Don’t Know Where To Start” series.

What Is the Best Fertilizer for Winterizing?

While I’ll try to be very careful not to mention any brand name right now, I’ll share a few specifications you should check out when you’re shopping for a winterizing fertilizer.

If you’ve been winterizing for some years now, then I guess you’ve probably heard that that the best winter fertilizers should have low Nitrogen and high Phosphorus and Sulphur. Although this used to do the job for us, recent research shows otherwise. An ideal winterizer should contain mostly Nitrogen, and the Nitrogen should be a quick-releasing water-soluble Nitrogen instead of as opposed to slow-releasing water-insoluble Nitrogen.

For the few of us that prefer organic fertilizers, we’ll be very limited in option if we’re seeking a fertilizer that is made of mostly quick-release Nitrogen. You might want to consider fast-acting liquid fish fertilizers that are 80% water-soluble but with an odor.

4 Steps to Winterizing your Grass

#1 – Check the PH Level of Your Lawn Soil

You’ll need to know the PH level of your lawn soil to know the right amount of Nitrogen your fertilizer should have. To check the PH level of your soil, you’ll need your soil sample of at least 4 inches to get a correct sample of the root zone.

A healthy lawn should have a neutral PH level; otherwise, you should try to neutralize it before it thins out over time. For an alkaline lawn, you’ll need Sulfur treatments, and for an acidic lawn, you’ll lime products to neutralize it.

#2 – Remove Weeds

While your grass will be dormant during winter, you don’t know about weeds. Winterizing your grass is all about trying to keep your plant healthy, so you should weed your farm to avoid unnecessary competition form perennial weeds when your grasses are vulnerable.

You just have to tour your lawn and remove any remaining weed, before raking away the debris and other stuff.

#3 – De-thatch Your Lawn

Your lawn might be susceptible to diseases, but if you can detach your lawn, you’ll avoid that. While a thin layer of thatch is beneficial, more than half an inch can be harmful. You can easily de-tatch your lawn with a thatching rake or a power de-tatcher.

#4 – Aerate to Refresh the Lawn

Now you’ve spread the fertilizer evenly, what next? While it’s not a compulsory process, aerating treats soil compactions, and ensure that air, moisture, and nutrients can reach grassroots. And yes, aerating is very simple. There’re several ways to aerate your lawn, but for a starter, I’ll recommend using an aerator.

#5 – Overseed Your Lawn

After aerating your lawn, you’ll notice some sparse areas around your lawn. To maintain a thick and green lawn, you can cover theses spaces with seeds that’ll grow come Spring. Also, in the Fall, warm-season weeds will die off and leave space for new grasses to grow. So overseeding your lawn won’t just give you a denser lawn, but you’ll also have more grass for a lesser competing weed.

#6 – Spread Fertilizer Evenly of Burn

We’ve talked so much about applying without emphasis on what could happen is you fail to do it well. Winterizing fertilizers are quite different from what you’d get from your regular spring fertilizer supply, especially since it has more Nitrogen and Potassium content. The best way to fertilize your lawn during this period is to use spread it evenly and sparingly over the grass, otherwise you may burn the lawn if over-fertilized.

Tips to Fertilizing Your Lawn During Winter (400)

Never fertilize later than early November, or your grass will keep growing instead of entering the dormancy period and be susceptible to frost damage.

If you have sprinklers or automatic irrigation systems, shut it down for winter.

What Happens If I Don’t Fertilize My Lawn in The Winter?

Winterizing is all about making your lawn lush and thick come Spring, but that doesn’t mean your grass will die if you don’t. It’s more like a security measure to make sure your grass survives the winter and looks good early summer. And if you missed it summer, and your grass survives, then you should consider early fertilizing during winter, sparingly.


Without much ado, here’s a quick recap of almost everything you need to know about winterizing your lawn.

Winterizing your lawn is essential to maintain a thick and green lawn through Spring, and it’s quite simple. Check your lawn’s PH level if you don’t already know, try to balance it, remove the weeds, and apply the fertilizer. Lastly, you’ll want to aerate your lawn to make sure even the root system gets the oxygen it needs. And overseed your lawn to make sure it’s thick with little weed competition come Spring.

Once you’ve winterized your lawn, you can go ahead to pack your stuff and wait for a beautiful and lush spring.