Understanding What Fertilizer Does for Your Grass

If you’re hoping to grow a lawn that draws envy from your neighbors, then you’ll need to understand the role of fertilizer and its importance. Fertilizer is a crucial component in promoting strong root growth, vibrant color, and overall plant health.

But with so many options to choose from, picking the perfect fit can be complicated.

To make an informed selection, you’ll need to get to the root of fertilizer’s role and how it helps your grass. It offers essential nutrients your grass requires to flourish, including nitrogen, phosphorous, and potassium. These nutrients promote root development, color and texture improvements, and pest and disease resistance.

The Basics of Fertilizer

Before we start into the specifics of fertilizer and why it’s important for your grass, let’s lay down the groundwork, beginning with the basics.

What is Fertilizer?

Fertilizer is a substance that supplies essential nutrients to your grass to aid in its growth. The material is used as an additive to ensure your grass has what it needs when it needs it. You’ll find three critical nutrients in most fertilizers: nitrogen, phosphorous, and potassium.

Generally, the trio is expressed as NPK, but you’ll see it represented as three numbers on the fertilizer label.

Why is Fertilizer Important for Your Grass?

Like any other living thing, grass requires certain things to grow and flourish. For example, we wouldn’t get very far without food, water, and oxygen. It’s the same story for grasses, like those that make up your lawn.

Fertilizers provide essential nutrients your grass needs to grow and thrive. While richer soils may provide the essentials, not all soils contain everything the plants need to flourish. Without fertilizer, the grass might not get enough from the soil, leading to patchy, weak, or stunted growth.

On top of the essential nutrients they provide, fertilizers aid in keeping your grass strong enough to resist disease and pests. They can even improve the color and texture of your lawn, resulting in a better-looking yard!

However, fertilizer isn’t a one-size-fits-all story. Instead, you’ll need to select an option that accommodates the specific needs of your grass. These needs vary from one grass type to another, as each requires particular amounts and ratios of nutrients, so ensure you carefully read the label and pick an appropriate fertilizer.

Once you select the proper fertilizer, follow the application instructions carefully to ensure you don’t over-fertilizer, as that can detrimentally impact your lawn, not to mention the environment,

Different Types of Fertilizers

Like many products, fertilizers come in a few different types. Each option has its place, as grasses have different nutritional needs, and homeowners have varying preferences.

Organic Fertilizer

25 lb. Lawn Food Fertilizer

If you prefer the natural approach to lawn care, organic fertilizer is the way to go. They make an excellent choice for those concerned about chemicals, as these options are environmentally friendly and safe for kids and pets.

These fertilizers feature natural ingredients, including compost, manure, and bone meal. The ingredients are carefully selected to produce the same results but offer a chemical-free approach. They provide a slow release of nutrients, enriching the soil structure and its water-holding capacity in the process.

Inorganic Fertilizer

Inorganic fertilizers are widespread, as they feature easily accessible synthetic materials, usually made from mined materials or chemical compounds. These options are typically more concentrated and act much quicker than organic fertilizers, delivering nutrients to the lawn in a quick hurry.

While these fertilizers offer a quick boost of nutrients to your lawn, they can negatively impact the soil health and surrounding environment if overused. Because of the potential adverse side effects, following application instructions to avoid over-application carefully is essential.

Slow-Release Fertilizer

As the name implies, slow-release fertilizers are specifically designed to release their nutrients over a longer period gradually. They come in organic and inorganic forms, so you can choose the option that best reflects your preferences.

These fertilizers are ideal for people who don’t have the time or desire to frequently fertilize their lawns, as it can get to be overwhelming for busy folks. Since these fertilizers are slow-release, they aid in preventing nutrient runoff and leaching, both of which can harm the environment.

Liquid Fertilizer

Liquid fertilizers are a staple in lawn care subscription services and are a popular pick for folks seeking a quick and easy fertilization method. They come in organic and inorganic forms and offer a quick boost of nutrients to your turf grass.

However, while they’re undoubtedly convenient, they can be more expensive than other options. In addition, they may require more frequent applications, as they act as a quick-release option.

Ultimately, choosing the best type of fertilizer hinges on varying factors, including your personal preferences, budget, and the specific needs of your lawn. As you weigh your options, consider things like your lawn’s soil type, grass species, local climate, and the amount of sunlight and water your lawn receives.

Once you select the perfect fertilizer, carefully read the instructions and follow them to a tee, as overusing fertilizers can harm your lawn and the environment.

Understanding Fertilizer Labels

Scotts Turf Builder Weed and Feed 3; Covers up to 5,000 Sq. Ft., Fertilizer, 14.29 lbs.

As you shop for fertilizers, you’ll come across various labels featuring numbers and symbols. While they might seem foreign at first, it’s essential to understand these labels, as they’ll help you choose the best fit for your lawn. Here are a few key things to watch for:

N-P-K Ratio

The three numbers you see on the fertilizer label tell you the N-P-K ratio, or the percentage by weight of nitrogen (N), phosphorus (P), and potassium (K) in the fertilizer.

For example, a fertilizer featuring a 10-10-10 label contains 10% nitrogen, 10% phosphorus, and 10% potassium. Plants have different needs, so choosing the appropriate fertilizer with the best NPK ratio for your lawn is crucial.

Secondary Nutrients

Aside from N-P-K ratios, it’s essential to consider the secondary nutrients in the mix. Fertilizers often feature a few secondary nutrients that, while not as vital as the aforementioned nutrients, are important for plant growth.

The secondary nutrients may include calcium (Ca), magnesium (Mg), and sulfur (S).


Last but not least, fertilizers also contain micro-nutrients that are essential to plant growth. However, unlike the previous nutritional elements, these nutrients are necessary in much smaller quantities.

These nutrients include iron, boron, copper, manganese, zinc, chlorine, and cobalt. Many soils contain at least some of these micro-nutrients, but since that isn’t always a given, adding them to your lawn via fertilizer helps ensure your grass has everything it needs to thrive.

By understanding the basics of fertilizer labels, you can select the best fertilizer for your lawn, ensuring your grass receives all the nutrition it needs to remain thick, green, and healthy.

When and How to Fertilizer Your Lawn

Choosing the correct fertilizer is only one piece of the puzzle. Although essential, it’s only one thing you need to consider when caring for your lawn. The others? When and how to fertilize your lawn.

Seasonal Timing

Some seasons are better for fertilizing than others, but the best time to fertilize your lawn depends on your grass type. Warm-season grasses thrive in late spring and early summer when temperatures hover between 80 and 95 degrees Fahrenheit.

Conversely, cool-season grasses prefer the chill of spring and fall when temperatures are between 60 and 75 degrees Fahrenheit.

The best time to apply your fertilizer is when the soil temperature hits a specific point, not when the air temperature achieves a certain level, as the two are very different. Generally, the ideal soil temperature for fertilization is 55 degrees Fahrenheit.

Application Methods

Scotts 76232 Turf Builder EdgeGuard DLX Broadcast Spreader, Single Pack, Green

There are several ways to apply fertilizer to your lawn, and the best option hinges on the type of fertilizer you’re using. Since many folks opt for a granular fertilizer, spreaders are the most common application option.

They come in a few designs, including broadcast spreaders, which are ideal for large lawns. Drop spreaders are perfect for small lawns, and handheld spreaders are suitable for small areas or spot treatments.

If you use a liquid fertilizer, you’ll usually use a hose-end attachment to apply it. The attachment might come with the liquid fertilizer purchase, but it depends based on the product and brand.

Watering After Application

Once you complete the application process, watering your lawn is essential. A good dousing of water helps activate the fertilizer and settle it into the soil, but it also helps prevent the fertilizer from singing the grass.

Water the grass immediately after applying the fertilizer, then continue to water it regularly over the next few weeks. Don’t overwater, as this can lead to fertilizer runoff and waste.

The perfect timing to apply your fertilizer hinges on your grass type, but the ideal soil temperature is 55 degrees Fahrenheit. You have a few options for application, including spreaders and hose attachments (depending on the fertilizer form). Once you apply the fertilizer, don’t forget to water it in to activate it and prevent it from burning the grass.

Common Fertilizer Mistakes to Avoid

Many folks make a few common mistakes when fertilizing, each of which can have unwelcome effects. So, to help your application be successful, here are a few common fertilizer mistakes to avoid:


While the thought of too much fertilizer might not seem like a bad thing and might seem to promise healthier grass, this isn’t always the case. Instead, overfertilization can actually harm your grass, causing it to grow rapidly and become susceptible to disease and pests.

On top of that, your lawn can only absorb so much fertilizer, so the excess may leach into the soil and contaminate groundwater. Once it ends up here, it can harm plants and animals, wreaking havoc on the environment. So, to avoid over-fertilizing, remember to carefully follow the instructions on the label and enlist the help of a soil test to properly determine the correct amount of fertilizer for your lawn.


Under-fertilizing is the opposite problem of over-fertilizing, but like the latter, it can lead to problems. Without enough nutrients, your grass may become weak, thin, and yellow, potentially becoming more susceptible to disease and pests.

So, ensure you apply the correct amount by following the label’s instructions and using a soil test to determine the proper amount.

Applying Fertilizer to Wet Grass

While you need to water after applying fertilizer, you shouldn’t apply it to wet grass. The dampness on the grass can lead to clumping in the fertilizer application, making it tricky to spread evenly.

On top of that, it can cause the fertilizer to cling to the grass, potentially burning the blades. So, avoid this issue by solely applying fertilizer to dry grass, avoiding applying before or after heavy rainfall.

Not Reading the Label

Every fertilizer is unique, so the accompanying label will boast its instructions. Failing to read the label can lead to a host of issues, including overfertilization, under-fertilizing, or applying at the wrong time.

Ensure you read the label carefully before using the product on your lawn, paying close attention to recommended application rates, timing, and special instructions.

Leave a Comment