What Does Nitrogen do for Grass

What Does Nitrogen Do For Grass

Whether you’re a new or old homeowner, you’ve probably heard somewhere that nitrogen was good for your lawn. Maybe it was on a television commercial, or an ad popped up one day when you were browsing through your social media.

In any case, that’s exactly right: nitrogen helps grass grow.

In fact, it’s the single most important nutrient to pay attention to if you want an orderly, lush, well-groomed lawn.

That said, there’s definitely some confusion out there about exactly how nitrogen affects your lawn’s grass, as well as how much you need and how to find a fertilizer that works for you and your lawn.

You also might not know how to spot whether your grass is getting too little (or too much) nitrogen. Many people only vaguely know that their lawn needs some form of nitrogen, without knowing exactly how much or at what intervals.

This article should help clear those issues up. Keep reading for a little info on what nitrogen does and how it works, as well as how to make sure your lawn is getting enough on a through fertilizer choice and the frequency with which you administer it.

How Does Nitrogen Work?

Nitrogen is an essential nutrient for plants. It’s responsible not only for the beautiful green color that you see in plant stems, but also for growth itself. It’s an essential element of chlorophyll, or the green pigment plants use to produce energy and feed themselves. Without nitrogen, plants can’t produce enough chlorophyll, which means they won’t grow tall and strong. They’ll be weak and brittle, have undersized fruit/seeds, a disproportionate amount of root to stem, or have a color that looks off.

All that holds true for grass as well. That’s probably why you hear words like “nitrogen-rich fertilizer” being used a lot — nitrogen is necessary for growth and good color in your lawn, and not having enough will lead to a sad-looking lawn. Nitrogen is important to any plant’s metabolic processes, and not having enough will inhibit a plant’s chance to grow and to recover from illness or injury.

You can think of nitrogen for plants the same way you think of vitamins in humans. For example, magnesium is a vital electrolyte our body needs for the most basic metabolic functions. It’s responsibly for building bones and maintaining a healthy skeletal system, but it’s also a necessary human nutrient in terms of regulating muscle contractions. Basically, it just does a lot. As such, a magnesium deficiency might lead to a variety of different symptoms: muscle cramps and pains, fatigue, weak bones and more.

Nitrogen is the exact same. Grass and other plants take in nitrogen when it’s in non-gaseous forms like nitrate or ammonium. Then, the nitrogen is used for a wide variety of basic processes, like making proteins for energy or creating the DNA and RNA cells need to replicate. And because nitrogen is an essential component of chlorophyll, plants literally need it to feed themselves.

The good news is, nitrogen isn’t hard to find. It’s abundant in both the earth’s atmosphere and the soil surrounding your grass. In fact, there’s about four times as much nitrogen in the air you breathe everyday than there is oxygen.

So why do you need nitrogen fertilizers, if nitrogen is so abundant in the atmosphere?

The answer is because plants can’t actually absorb most of the nitrogen in the atmosphere, which is in gaseous form. Nitrogen needs to go through a process called “fixation” and be converted into a form that plants can actually use.

They need to use their roots to absorb it through the soil, which means plants only get a small fraction of the nitrogen available to them. Fertilizers allow you to add more nitrogen to the soil plants use so that they get the nutrition they need, which in turn helps them grow.

In fact, if you want a green, lush lawn, then using a nitrogen fertilizer isn’t just an optional addition to watering your plants; it’s actually necessary. No matter how much sun or water your plants get, without using a fertilizer there may just not be enough available nitrogen for them to grow healthily.

What Are Nitrogen’s Benefits For Your Lawn?

As mentioned above, nitrogen is the most important ingredient for basically all of the everyday plants you see when you walk outside. For grass, this means nitrogen is important in a couple of different ways.

For one, it’s essential to color. If your lawn has an adequate amount of nitrogen, it’ll look lush and green. The color will also be consistent throughout the area, without any particularly yellow or orange looking patches scattered around.

Nitrogen is also necessary for growth. Grass with the proper amount of nitrogen will grow fairly quickly, requiring a trim every week or two in the summer months. Exactly how quickly your lawn grows/needs to be cut will depend on a variety of other factors as well, such as climate and elevation, but nitrogen is a crucial component.

Finally, nitrogen is also necessary for your lawn’s appearance of fullness or lushness. Without nitrogen, the grass will be stunted; it may be rather short or sparse, rather than covering the lawn evenly and fully. With enough nitrogen, the grass will appear tall and thick, and individual blades will look they way they should.

See my full grass growing guide here for more helpful tips – no opt-in needed.

What Does Nitrogen Deficiency Look Like?

The fact is grass needs nitrogen — and quite a lot of it. If your lawn isn’t getting enough nitrogen, then you’ll definitely know, as the signs are completely visible to the naked eye.

Nitrogen-deficient grass will have an off color; it’ll look yellow or orange rather than the usual green. Also, because nitrogen is important to plant growth, your grass will likely be smaller or more stunted than usual; you may find you haven’t had to cut it as frequently as you normally do. If you examine individual blades of grass, they may have an unusual shape. Finally, your lawn as a whole may be patchier and less even/lush than is usual.

In fact in some cases moss growth in the lawn may also indicate your nitrogen levels may be imbalanced with the other micro and macro nutrients. Too much nitrogen paired with excessive watering can cause moss.

Is There Such A Thing As Too Much Nitrogen?

Unfortunately, it actually is possible to give your grass more nitrogen than is healthy for them. This may be more of an issue for synthetic nitrogen fertilizers rather than organic ones.

Over-application of nitrogen can “burn” your lawn, producing spots or streaks of brown, dying grass.

To avoid burning your lawn, don’t apply fertilizer too frequently, and make sure you always water your lawn gently after you apply it. Also, even if it doesn’t look like the fertilizer you currently use is having any effect, don’t rush to try out a new one until the next scheduled fertilization cycle; overlapping fertilizers is another great way to accidentally burn your grass.

If your lawn does end up being burned by nitrogen, the first step is to water it gradually and monitor the effects. If you notice new grass growing underneath any dead spots, then you can simply continue to water and weed as you regularly would. On the other hand, if you realize that certain dead spots are persisting, you may have to resoil and reseed that area to ensure fresh growth.

How Do I Find The Right Nitrogen-Based Fertilizer For Me?

When choosing a fertilizer for your grass, reading the label (and not just the marketing headline on the front of the bag!) is incredibly important. That’s partly because, as we’ve just covered, it’s a definite possibility that you’ll end up giving your plants either too little or too much nitrogen.

A potential buyer should make sure that any fertilizer you choose has a higher nitrogen content than it does other essential nutrients that plants needs, like phosphorus or potassium. Most bags of fertilizer should have the three percentages listed relatively prominently on the label (it might say N for Nitrogen, P for Phosphorus and K for Potassium).

Another consideration is how quickly the nitrogen gets released into the soil. Bags of fertilizer that say “slow release” are pretty self-explanatory; the nitrogen simply gets released more slowly over time into the soil. If you buy slow-release fertilizer, you can expect to need to reapply it once every two months or so rather than once per month, depending on your climate and watering/cutting schedule.

Finally, the last big thing to consider is whether or not your chosen fertilizer comes in granule or liquid form. Granule fertilizer is likely easier to spread if you’re a homeowner, if you don’t have specialized equipment or if you don’t use fertilizer very often. It’s also usually cheaper than liquid alternatives. That said, pros may want to take a look at liquid fertilizers, as they can generally be spread more evenly and plants can also more readily absorb them because they’re in liquid form.


Nitrogen is totally essential to grass in any form! It’s a necessary nutrient for plant life, and that’s especially true for your lawn. Without an adequate amount, grass can’t grow healthily and consistently. And even though the earth’s atmosphere is rich in nitrogen, plants can’t absorb it in its gaseous form; they only get it through the soil.

That’s why it’s so essential to fertilize your lawn with nitrogen-rich fertilizer; if you want the textbook green lawn with a white picket fence, fertilizer is a necessary component. That said, it’s definitely possible to give your lawn too much nitrogen, which will have the opposite effect and may burn your grass, so be careful. But as long as you use nitrogen in moderation and keep an eye on your lawn, you should be on the way to a picture-perfect front yard in no time.