7 Tips for Applying Winterizer Fertilizer

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All spring and summer, you have diligently worked in your yard. You have likely invested a lot of blood, sweat, and tears to create a lush oasis that has provided rest and relaxation for your and your loved ones.

But now, colder weather is on the horizon. You might already see the signs that animals and plants alike prepare for the coming winter. The growing season is coming to an end.

You might notice a chill in the air, and you don’t need to mow your grass as frequently anymore. Nature, much like a bear, is getting ready to hibernate.

Perhaps you are looking forward to the reprieve to your yard work that late fall and winter will bring. Perhaps you are ready to sit back and relax in different ways for a few months.

But there is one more thing you should consider doing, if you don’t want to jeopardize all the effort and money you have invested in your lawn.

To ensure that you garden remains a focal point of your property when spring comes around again, you should help your plants prepare for the cold months ahead.

It turns out that preparing your lawn mower for storage is not the only thing to do. Applying a winter fertilizer, or winterizer, is an important job to consider before the yard work is done for the year.

Winter fertilizer is needed to prepare your lawn for the winter.

What is a Lawn Winterizer?

Simply put, a lawn winterizer is a late-fall application of fertilizer that is meant to help your lawn store nutrients for the upcoming winter. 

The application of a lawn fertilizer in late fall will not only help your yard survive the winter but also encourage hearty and rapid growth and rooting when spring rolls around again.

Cold grass need lawn winterizers to survive.

When to Apply

It is important that you understand the function of a lawn winterizer.  This type of fertilizer is used in preparation for the cold weather and should not be applied in the winter.  So don’t be confused by the name of this product.

It is important to know the best time to spread a winterizer on your lawn.

The best time to apply this kind of plant food is late fall, as soon as the grass stops growing.  Take note that we said “as soon as” in that sentence.  It is essential that the lawn is still green on top and the roots are still active.  This means that the grass is still actively absorbing nutrients from its environment.

Winterizers are used only on cool-season grasses like bluegrass and fescue. 

Warm-season grasses such as St. Augustine and bermudagrass usually go dormant once the first frost strikes.  The final fall application of plant food should sustain these types through the winter.

Giving your lawn a late-season boost is a very important part of overall lawn care all over the country, but it is especially true for grass types found in the northern parts, where winters can be quite brutal.

If your lawn features bluegrass or fescue, plant food can be applied as early as mid to late November.  This should be late enough in the year for the grass to have stopped growing.

You can apply the product as late as early December.  However, it all depends on when your lawn stops growing in the fall.  This is obviously subject to the weather conditions in your region.   Still, a good rule of thumb is not to apply a winterizer after early December.

Fall is the best time to apply lawn winterizer

What’s the Difference Between a Spring and a Winter Fertilizer?

The application of lawn fertilizer, whether spring or winter, is essential to proper lawn care.  It is important to understand the differences between the two to ensure appropriate applications of each.

As discussed above, a winterizer is used on your lawn late in the year.  In contrast, a spring fertilizer can be used from spring through the early fall.

This latter product is designed to be applied during your yard’s growing season to support grass growth across your lawn. 

A winterizer is applied to your lawn to provide nutrients to the grass and soil in preparation for the colder months of the year, when plants are dormant. This helps plants to be ready for healthy, rapid growth in the spring.

Unlike a winterizer, the spring variety can be used on both cool and warm-season grasses.

Healthy lawn after proper fertilization

Winter Fertilizer Numbers

The use of these two different types of fertilizer supplements affects your lawn in very different ways, and this is reflected in the products’ nitrogen, phosphorus, and potassium number ratios.

The nitrogen is there to promote the growth of grass’s green leaves and stems.  As such, the nitrogen content in a spring fertilizer is higher than the nitrogen content in a winterizer.  What use would the nourishment be if it didn’t make your lawn lush and green?

The booster product you apply in late fall or early winter is not meant to promote grass growth and thus, a lesser amount of nitrogen is needed.

But nitrogen content is not the only difference in nutrients between the two.

Winterizers are considerably higher in potassium content than their spring counterparts.

Potassium promotes the overall health of the plant from top to bottom.  A healthier plant is better able to tolerate the cold and stress.  Using a product with high amounts of potassium will adequately prepare your lawn for the winter weather.

One important thing is to know the N-P-K ratio of your winterizer BEFORE spreading it on the lawn. This is essential to ensure you are providing your yard with the food and care it needs to prepare for the weather after November.

For example, Scotts Winterguard fertilizer has an N-P-K content of 24-2-14, while the standard Turf Builder has an N-P-K content of 29-2-4.  While different brands may have different ratios, the K content will always be much higher in products for late-season application and the N content will be somewhat lower.

Maintained lawn in fall needs winter fertilizer to allow it to survive the cold.

Is a Winterizer Necessary?

You need to consider several points before applying a product to your grass that prepares it for colder weather. 

First, as we already said, a winterizer is designed to be used on cool-season grass. 

So, if you live in the southern part of the country, there is a good chance that your grass may never go dormant.  If this is the case, then obviously using a winterizer product is not necessary.

Likewise, if your yard is primarily made up of warm-season grass, it will probably go dormant with the first frost, but it can store what it needs for the winter with the help of an early-fall application of fertilizer.  In this case also, your lawn is not in need of a boost at the end of the season.

However, if you live in an area with pronounced winter weather, using a winterizing product would be very beneficial.

Before applying a fertilizer, you should perform a soil test.  Testing the soil in the fall will give you an idea of the kind of wear and tear your yard has experienced throughout its growing season.

If your soil is healthy with a higher amount of K than you would normally expect, then you may not find it necessary to apply a winterizer.  

Icy grass covered in snow, but still alive

6 Tips to Applying a Winterizer

  1. Ideally, you should try to apply a winterizer in mid to late November.
  2. Try to avoid applying after the early part of December.
  3. Check the package for a proper NPK ratio, and make sure that the nitrogen is water-soluble.
  4. Only use ⅓ to ½ of the amount of fertilizer recommended on the package.  This is an old lawn care professional trick to extend your lawn’s life as the prescribed amount will often end up being overkill or scorching the turf.
  5. Conduct a soil test before fertilizing.  If it shows adequate levels of K, then you won’t need the booster.
  6. If you feed your lawn with an organic fertilizer or compost through the warmer months, you probably won’t have to worry about winterizing.  There should be enough K available in the soil to last through the winter.
  7. Carefully inspect any package labeled winterizer, as some of these do not have the correct NPK ratios and are merely marketed that way.

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About the author: Jeffrey Douglas is a horticultural hobbyist that loves everything related to plants and gardening. He specializes in gardens and houseplants.

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