How Exactly Does Fertilizer Help My Lawn?

As you might have guessed from our name, fertilizing lawns is something we do best! But what exactly does that mean? What is it in fertilizer that greens up our grass, makes it tougher against stressors, and keeps broadleaf weeds at bay? If you’ve ever wondered how the magic of lawn fertilizing works, here’s the answer.

How Fertilizer Functions In Your Lawn

Fertilizers come in many forms and with different ratios of nutrients, but they all contain the same three macronutrients and micronutrients that our lawns need. You may have noticed that fertilizer has a series of three numbers on it, like 16-12-12 or 3-3-3. This informs you of the proportion of nitrogen, phosphorous, and potassium – in that order. Your lawn needs all three minerals, but overdoing them can offset the balance we want in the lawn. This is a tricky part of lawn maintenance, but your lawn service technician will help you determine which fertilizer mixture is right for your lawn.NPK

The Macros


This is probably the most well-known of the three macronutrients. It’s a popular choice at the beginning of the growing season in spring because, depending on how you apply it, it can green up your lawn very quickly. Unfortunately, many homeowners don’t realize that if you want to have a vibrantly green lawn next spring, you’ll need to reapply fertilizer in late summer and fall. Nitrogen helps with leaf development, chlorophyll formation, and photosynthesis. And it comes in two different forms to meet the changing needs of the season: slow-release and quick-release.

Fast-release fertilizer is typically water-soluble. It often comes in a bottle you attach to your garden hose so you can spray it over the lawn. Be careful when using this fertilizer because it may cause a large flush of uneven growth. You might have seen a high schooler prank their classmates by “writing” something on the football field. This is done by applying fast-release fertilizer so that the “message” appears as darker green grass. The downside of seeing that quick green is that, because it’s water-soluble, it tends to dissolve quickly – especially if there’s a lot of rain, as we have seen this summer here in Michigan. This means you might have to reapply it.

In late summer and early fall, we’d recommend a slow-release fertilizer so that it lasts into the cold weather. These fertilizers tend to be granular so that they will dissolve more slowly. We’ll talk more about the different forms of fertilizer later.


Phosphorous is needed for early root growth, seed formation and helps grass reach maturity faster. Mature grass is more likely to tolerate dips in temperature and stand up to broadleaf weeds, surface insects, and lawn diseases.


Potassium toughens up grass – something we need in Michigan during the heat of summer. While this summer has been quite rainy, the past few years have seen the opposite, and without rain to supplement watering schedules, grass can become brittle and have a hard time recovering. Keeping a balanced potassium level in your lawn will help your grass regulate its processes and boost the grass’s tolerance to stress and drought. Potassium also aids with root growth and stem development.

The Micros

Micronutrients are just as important as macronutrients, but your lawn doesn’t need as much of them – in the same way, that humans need certain vitamins more than others. These minerals are boron, chlorine, copper, iron, manganese, nickel, and zinc. Like the macronutrients, they assist your grass with processes like chlorophyll production, photosynthesis, DNA synthesis, disease resistance, and other vital functions.

Types of Fertilizerfertilizer in hand

Fertilizers come in several different forms, depending on what you need to get out of them.


This could include agriculture manure. If you didn’t know, many farms will repurpose all that cow poop to use as beneficial fertilizer for lawns and gardens. These fertilizers are easier for the lawn to digest and will break down slowly over time. This is a good solution for homeowners who want to keep things natural.


These types of fertilizer are water-soluble and fast-acting. If your lawn is damaged, or you haven’t yet fertilized this season, this might be the way to go.


Like organic fertilizer, this form of fertilizer is slow-release. The granules will slowly break down and melt into the lawn instead of dissolving quickly like the liquid or synthetic options. It’s a good idea to use this at the end of the season, so your grass has nutrients all winter long.


Liquid fertilizer will green up your lawn quickly and is typically less expensive than other forms. We’ll mix it in with water so your lawn will get a nice dose of hydration and nutrients at the same time!

Get Professional Fertilizer And Lawn Care Near Grosse Ile

Save yourself the time and energy researching what fertilizer is best and leave it to the pros at Grosse Ile Lawn Sprinkler & Fertilizing. We’ve helped thousands of homeowners find the perfect balance of nutrients for their lawns. Our fertilization is part of our six-step lawn care service program, or we could always do a specialized treatment for a lawn in need of rescuing. Call (734) 285-4470 or leave us a message online to learn more or schedule an appointment.

Don’t forget to check back next month for our latest blog post! And you can like us on Facebook, where we post the latest deals and share photos of green happy lawns!

We Partner with Local Home and Business Owners

Grosse Ile Lawn Sprinkler & Fertilizer services several cities and towns in Wayne County and across several other local communities including:

Woodhaven, Michigan

Collaborating with Woodhaven residents to create a results-driven solution that breathes new life into their yards, beds, and gardens.

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Flat Rock, Michigan

Leading the way in the Flat Rock market as a trusted partner for all things lawn & sprinkler, fertilizing, and more.

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Brownstown, Michigan

Transforming Brownstown lawns, yards, and landscaping with our unparalleled customer care and expertise

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Trenton, Michigan

Partnering with Trenton home and business owners to revitalize their properties with our full suite of services.

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Grosse Ile, Michigan

Serving the people of our hometown since 1986 to keep the community’s natural beauty as elegant as possible.

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