What Does Nitrogen Do For Grass? Should You Add It?

To maintain a healthy lawn, it is important to fertilize your grass regularly.

The three main nutrients in lawn fertilizers are nitrogen, potassium, and phosphorus.

Nitrogen is considered an essential nutrient for your lawn, so what does it do for your grass? 

Do you need to add it to your lawn maintenance routine?

Nitrogen is an essential element of chlorophyll, which gives grass its vibrant green color. Grass growth is also accelerated with a nitrogen-rich fertilizer. If your grass is not green and does not seem to be growing, adding nitrogen to your lawn is the best solution.

Using a nitrogen fertilizer on your lawn is easy to do, and within a few weeks, your grass will be lush and green.

Since nitrogen is such a key nutrient for your lawn, it is crucial to understand how to use it correctly.

Keep reading to learn more about what nitrogen does for grass and how to safely apply it to your lawn.

what does nitrogen do for grass 1

Why Does Grass Need A Nitrogen Fertilizer?

While nitrogen is naturally found in the atmosphere, grass and other plants cannot absorb this gaseous form of it.

Nitrogen must be converted to a usable form, known as nitrate, to fertilize the grass.

Grasses absorb nitrogen and other essential nutrients through the healthy soil down into their roots.

With a strong root system, the grass can grow and stay healthy.

If there is not enough nitrogen in your soil, you will need to add it periodically.

Adding a nitrogen-rich fertilizer to your lawn is essential if you want your grass to be green, lush, and resistant to disease.

Even with ample sunlight and regular watering sessions, there will not be enough naturally available nitrogen to keep your grass green and healthy.

Nitrogen fertilizers come in fast-acting and slow-release formulas. 

These different formulas allow you to apply the nitrogen to your grass according to what your lawn needs.

Fast-acting nitrogen fertilizers are inexpensive and offer quick results, but they will need to be applied more often than the slow-release formulas.

Slow-release nitrogen fertilizers work well when applied at the end of the growing season because the grass can store the nitrogen it needs to revive in the spring.

Thanks to these nitrogen stores, the dormant grass will then grow back green and healthy at the start of the new growing season.

Nitrogen Makes Grass Grow Faster

If your lawn is receiving plenty of sunlight and water, but your grass is still thin and stunted, it is time to add a nitrogen fertilizer to your maintenance routine.

When grass receives the right amount of nitrogen, it will grow faster, and the individual blades will be wider.

You will likely have to mow your lawn during the peak growing periods once or twice per week.

When the weather is very hot during the summer, grass growth will naturally slow down. 

This slowed growth means you may only need to mow the lawn once every week.

It is important to follow proper mowing guidelines and only cut up to one-third of the grass length at one time.

A grass height of around 3″ inches is optimal for most grass types.

Cutting your lawn too short will result in yellow grass and bare spots because the plant will have more difficulty absorbing nutrients and moisture properly.

Nitrogen Creates A Lush Lawn

In addition to making grass grow faster, nitrogen also helps grass grow thicker.

Bunch grasses will grow more densely, and creeping grasses will cover the ground evenly, giving your lawn a more lush appearance.

A densely-grown lawn also works to suppress weed growth naturally.

An overgrowth of weeds on your lawn is very difficult to remedy without causing harm to any nearby grass.

Pesticides cannot distinguish between weeds and healthy grass, so they must be applied carefully.

It is much safer and easier to prevent weed growth by adding nitrogen to create a more lush, full lawn.

With the right amount of nitrogen, your grass will grow tall and thick for the entire growing season.

Signs Of Nitrogen Deficiency In Grass

what does nitrogen do for grass 2

Nitrogen is responsible for giving the grass its vivid green color.

When a lawn receives the proper amount of nitrogen, the green grass color will be consistent throughout the entire area.

The most obvious sign of a nitrogen deficiency will be a discoloration of the grass.

Nitrogen-deficient grass will have a pale yellow or brown color instead of green.

Another sign of a nitrogen deficiency in your lawn is stunted growth.

Your grass will be shorter than usual, and you may find you do not need to mow your lawn as often as usual.

The individual grass blades may be deformed or curl when there is a lack of nitrogen.

Without sufficient nitrogen, grass growth will be sparse, and your lawn will have bare spots.

These bare spots will make your lawn appear patchy, and it will lose its overall lush appearance.

On the other hand, if you begin to see areas of moss growth on your lawn, this indicates a nitrogen imbalance.

Too much moisture combined with a large amount of nitrogen will cause patches of moss to grow.

Is Too Much Nitrogen Bad For Your Lawn?

While moss is not inherently bad for your lawn, it will give your yard a patchy appearance and is usually considered undesirable.

Other side effects of too much nitrogen are more detrimental to your lawn.

Applying too much nitrogen to your lawn significantly increases the risk of burning your lawn.

Signs of a lawn burn include brown, streaky discoloration and dead grass.

Burns are more common in lawns treated with fast-acting synthetic nitrogen fertilizers rather than slow-release organic nitrogen sources.

The grass is more prone to burns when the nitrogen fertilizer is applied during periods of extreme heat.

Dry grass is also likely to burn from nitrogen fertilizer, so it is best to halt application when there are drought conditions in your area.

How To Safely Apply Nitrogen To Your Lawn

There are a few key things to remember if you want to safely apply nitrogen fertilizer to your lawn.

To prevent burns to your lawn, it is important to apply a nitrogen fertilizer according to the directions on the label.

Most synthetic nitrogen fertilizers require the lawn to be thoroughly watered after application, so it is not advisable to use them if there is a water usage ban in your area.

Applying a nitrogen fertilizer too frequently is also a common cause of lawn burns.

Keep track of when you fertilize your lawn, and do not fertilize more often than necessary.

Most lawn care experts recommend fertilizing your lawn according to holidays, such as Memorial Day, July Fourth, Labor Day, and Halloween.

This holiday schedule makes it easier to remember when to fertilize your lawn and prevents you from overdoing it.

Grass usually does not need a nitrogen fertilizer at the very beginning of the growing season.

As long as you have fertilized your lawn with nitrogen before it goes dormant for the winter, your grass will store the nitrogen for the entire dormancy.

Once the temperatures become warmer, the grass will use these nitrogen stores to revive itself.

When the growing season begins, your lawn will have enough nitrogen to become lush and green once again.

We have another post on how to keep grass green during the winter we recommend checking out if you want to start strong during the growing season.

Switching Fertilizers

If the fertilizer you are currently using does not produce any results in your lawn, do not add another fertilizer until the next scheduled application.

Weather conditions may affect how well your fertilizer works, so it is best to wait it out to see how your lawn reacts.

Combining different fertilizers greatly increases the risk of burning your grass.

Applying Granular Fertilizers

The most efficient way to apply a granular fertilizer is to use a broadcast spreader.

It is best to calibrate your spreader before you begin to ensure even application.

If your broadcast spreader applies too much nitrogen fertilizer, your lawn is more likely to develop burn lines.

The easiest way to ensure even fertilization is to apply the nitrogen to your lawn in a checkerboard pattern. 

To do this, you will apply half of the fertilizer while walking in a north to south direction and apply the other half in an east to west direction.

Using Grass Clippings As A Nitrogen Fertilizer

The easiest, least expensive, and safest way to add nitrogen to your lawn is to let your grass clippings do all the work.

Instead of bagging your grass clippings, allow them to fall onto your lawn when you mow.

Grass clippings are naturally rich in nitrogen, and it is released into the soil, along with other nutrients, as decomposition takes place.

Grass clippings do not need to be watered in to be effective, and they usually decompose completely within 2-3 weeks, depending on weather conditions.

Use a rake to evenly spread the grass clippings across your lawn to avoid clumping.

Unlike synthetic nitrogen fertilizers, grass clippings release their nitrogen slowly and prevent the risk of lawn burns.

Check out our list of other natural ways to add nitrogen to your lawn.

What To Do If Your Lawn Has Nitrogen Burns

There are a couple of things to do if your nitrogen fertilizer application has caused burns to your lawn.

Start by thoroughly watering the burned area and then monitor your lawn for any noticeable changes.

If you see new grass growth under the burned spots, keep watering your lawn to encourage healthy growth.

The burned areas of grass will eventually recover, and it is important to be patient and maintain a regular watering schedule to achieve the best results.

Do not fertilize any previously burned areas of grass until they have fully recovered.

If the grass is severely burned, it may not grow back at all.

When you see bare spots where the burned grass has completely died, it will be necessary to reseed your lawn to make it lush and full again.

Choosing The Right Nitrogen Fertilizer For Your Lawn

what does nitrogen do for grass 3

It is imperative to read the label on a fertilizer before deciding whether or not to use it on your lawn.

In addition to application instructions, the label will also include the nutrient content and whether the product is a fast-acting or slow-release fertilizer.

Understanding the numbers and information on the fertilizer label is vital when deciding if it is the right one for your lawn’s needs.

What Is N-P-K?

The N-P-K numbers on a bag of fertilizer represent the percentage of nitrogen, phosphorus, and potassium it contains.

For instance, if a bag of fertilizer has the numbers “3-1-2,” it means it is composed of three parts nitrogen, one part phosphorus, and two parts potassium.

When treating an already established lawn, look for a fertilizer with higher nitrogen content.

If your lawn has recently been seeded or if fresh sod has been installed, choose a fertilizer with more phosphorus.

Phosphorus helps the new grass establish a strong and healthy root system.

Fast-Acting Vs. Slow-Release

Another critical factor in choosing the best fertilizer for your lawn is how quickly the nitrogen is released into the soil.

Fast-acting fertilizers produce quick results, often turning lawns green and encouraging growth in as little as three weeks.

Inorganic fertilizers usually contain either ammonium nitrate, calcium nitrate, or potassium nitrate as nitrogen sources. 

These nitrogen sources are water-soluble, which is how they can work so quickly.

Because of their speedy results, fast-acting fertilizers must be applied once per month to maintain a lawn’s lush, green appearance.

Fast-acting fertilizers tend to be less expensive than slow-release versions, but the savings are negated by how frequently they are used.

There is also a higher risk of causing burns to your lawn when using a fast-acting fertilizer because their formulas are so concentrated.

Slow-release fertilizers are safer to use because the nitrogen is released into the soil over a longer period.

While slow-release fertilizers are more expensive, the benefits they offer to your lawn outweigh the extra cost.

In addition to reducing the risk of accidentally burning your grass, slow-release fertilizers only need to be reapplied every 2-3 months, depending on weather conditions in your area.

If you do not mind waiting for the results, slow-release nitrogen fertilizers are the best option for maintaining a green and healthy lawn.

The Benefits of Organic Fertilizers

Slow-release organic fertilizers offer more benefits to your lawn besides producing healthy growth with vivid color.

Unlike chemical fertilizers, organic fertilizers do not leave behind any toxic residues, which may cause problems with your lawn later.

These fertilizers are made from organic sources, such as animal and plant waste, and they compost into the soil better than synthetic formulas.

Not only does this composting release more nutrients into the soil, but it reduces the chance of having the fertilizer washed away during a heavy rainstorm.

Organic fertilizers also help your lawn retain more moisture, allowing you to reduce water usage by as much as sixty percent.

With most organic fertilizers, you also do not have to water the lawn immediately after application.

However, it is good not to apply any fertilizer to a dry lawn to avoid burning the grass.

Wait until the day after a watering session or a soaking rain to apply the fertilizer. 

This waiting period ensures the soil has enough moisture to absorb the fertilizer properly without being too soggy.

Using organic fertilizers is an excellent way to have a lush, green lawn while keeping maintenance to a minimum.

Commonly Asked Questions

How often can you apply nitrogen to your lawn?

Slow-release nitrogen fertilizers impart their nutrients over a prolonged period, so your lawn may go for 6-8 weeks between applications.

Fast-acting nitrogen fertilizers have to be reapplied every four weeks to produce consistent results.

The weather also plays a factor in how frequently your lawn will need to be fertilized.

When the weather is hot or drought conditions, it is best to wait for more favorable weather to start fertilizing again.

If your lawn has received a lot of rain, you may need to fertilize more often to replace the nutrients lost due to water run-off.

No matter what type of nitrogen fertilizer you use on your lawn, never apply more than one pound of nitrogen per 1,000′ square feet all at once.

What do nitrogen, phosphorus, and potassium do for grass?

Nitrogen encourages grass to grow and produces its vivid green color.

Phosphorus is used by grass to create a solid root system, fight disease, and produce new seeds, fruits, and flowers.

Potassium regulates physiological processes in grass plants, helps the plant stems grow strong, and accelerates the growth process by allowing nitrogen to be used more efficiently.

These three nutrients work in conjunction to help your grass grow strong, healthy, and lush.

What nutrients are in grass clippings?

Grass clippings will provide your lawn with up to 25% of its total required nutrients.

On average, grass clippings are 4% nitrogen, 1% phosphorus, and 2% potassium.

Regularly spreading grass clippings on your lawn every time you mow may allow you to extend the time in between scheduled fertilizing sessions.