How Much Nitrogen Can You Put On A Lawn?

How Much Nitrogen Can You Put On A Lawn

You’ve probably known from experience that your turf grass needs enough nitrogen to remain lush, healthy, and green. Most likely, you’ve also noticed that the “N” percentage in your NPK fertilizer almost always exceeds the other listed elements.

This is because, perhaps more than any other nutrient needed for plant growth, nitrogen provides the required support needed for vigorous plant development, it keeps the plant green, it helps it develop dense shoots and gives it the necessary stamina for resisting stress and insect pest.

For these reasons, lawn owners are usually faced with the temptation of applying just a little more nitrogen than is actually needed for plant growth. But as with all lawn care practices, “too little” is never good, and “too much” can be dangerous. “Enough” is usually all that is needed.

What You Need To Know About NPK

Plants require certain nutrients for healthy growth. Some of these nutrients are usually present and derived from the soil. But most time, not all the nutrients required to support sustained growth are made available. And this is where fertilizers come into play.

Nitrogen, phosphorus, and potassium are, by far, the essential nutrients needed by your plant. With N standing for nitrogen, P for phosphorus, and K for potassium.

On every fertilizer, liquid, or granular, you’ll normally see these three numbers written in dashes. They are a reference to the percentage quantity of such elements present in the fertilizer. What this simply means is that it indicates how much nitrogen, phosphorus, and potassium is present in the bag.

Nitrogen is a necessary requirement if you’re after a green and healthy lawn. Just the way we humans depend on oxygen for survival, same also, plants depend on nitrogen for their overall development.

Phosphorus, on the other hand, helps in healthy root development and early plant vigor. Depending on your turf’s growth stage, you might even discover that this is what it requires the most. In fact, this is usually the case when you have new and emerging seedlings.

Finally, on the list is potassium. Potassium helps to boost your turf’s resilience in dealing with adverse diseases and adverse temperatures. Fertilizers normally contain less of this because, most often, potash is normally found present in the soil.

For mature lawns, nitrogen is by far the most needed and the most used up out of the three.

Signs That Your Lawn Is Lacking in Nitrogen

It doesn’t take so long to discover a nitrogen deficiency in the soil. There are usually tell-tale signs that follow, and usually, they are easily identifiable.

Many at times, wilting and dead patches on your lawn, especially when there’s no heatwave, and you’re sure you’ve watered rightly, might be as a result of nitrogen deficiency. This is because nitrogen is responsible for chlorophyll formation in plants. And chlorophyll is what gives your turf its healthy green pigmentation.

Another sign you might want to watch out is chlorosis. This simply means the blades of your grass might begin to turn yellow or thin out in certain areas. Also, if you discover that after mowing, you have fewer grass clippings than before, that could be an indication that your soil is nitrogen deficient.

Signs That You Have More Nitrogen Than Is Needed

Usually, the first sign you might notice is that your grass might begin to burn out. This occurs because excess nitrogen scorches the plant tissue, thereby leading to it burning out. More so, excessive thatch might begin building up, thereby leading to a thatch problem in your lawn eventually.

The grasses might also grow too lush and lose stamina resulting in increased susceptibility to insect pests. Finally, excess nitrogen in the soil could lead to the growth of unwanted weeds, which is always a major scare for lawn owners.

How Much Nitrogen Does My Lawn Need?

Before applying more fertilizer on your soil, be sure to do a soil test. A soil test will reveal the elements that are deficient and hence, the right quantity required to remedy it. That being said, the amount of nitrogen that your lawn needs depend first on the results of your soil test.

Then, it’s also necessary to point out that your lawn size also determines the overall quantity of what will be needed. But as a rule of thumb, your lawn needs no more than one pound of nitrogen per 1000 square feet.

What this means is that if you have a 20-04-10 bag of fertilizer, you should apply no more than five pounds over every 1000 square feet. To promote vigorous growth, you could make it as much as two to four applications. Just make sure it doesn’t exceed the one pound of nitrogen rule per 1000 square feet.

Remedying the Effect of Excess Application

Mishaps do happen at times when applying fertilizers. And when this does, the effect is usually that your grass blades will end up with a fertilizer burn. The synthetic fertilizer in salt form, when dried up, leads to an eventual discoloration and a times death of the turf. When this happens, we describe it as a burn.

Beyond even its immediate effect on your turf, excess nitrogen can go on to leach from the soil and contaminate the water bodies around.

To prevent this from happening, immediately clean up the excess in the case of granular fertilizers. You should also immediately flush with enough water. This applies to both granular and liquid fertilizers. Doing so will greatly reduce the likelihood of burns as the majority of the fertilizer must have been washed off.

Fertilizer Application Tips

#1. Opt for Slow Release Fertilizers

Before settling on a nitrogen source, you might want to consider what type of release rate is appropriate for your turf. We could categorize this under two categories based. The fast release gives the lawn an almost instant boost. While slow-release fertilizers provide a steady and delayed release of nutrients.

With slow-release fertilizers, there are usually fewer chances of fertilizer burns occurring. Also, it provides longer-lasting feeding for your lawn, making it more economical in the long run.

This is not to say that fast-release fertilizers are disadvantageous. They help to provide an instant nutritional boost for your turf as well as treat pressing issues. Usually, their results come faster, with the effect being a quick greening and faster growth.

Organic fertilizers fall under the slow-release category.  This could be manure, grass clippings, coffee grounds, etc.

#2. Watering

Fertilizing your lawn without going ahead to water it in might prove abortive. This is even more important if you’re making use of granular fertilizer. They need to be watered in before they can become activated. But more importantly, they need to be watered to prevent fertilizer burns.

But be careful to ensure that you do not overwater to the extent where you cause the fertilizers to leach off. Also, a soggy lawn could lead to root rot, which is not something you should look forward to. Again, never forget nor neglect the number one watering principle “water deeply and less frequently.”

#3. Know Your Turf Type

Another factor that plays out when determining our fertilizing routine is the type of turfgrass we have. Warm-season grasses like the Bermuda grass or the Buffalo grass favor the application of fertilizers during late spring, and early summer as that is the period when they are growing most rapidly.

On the other hand, cold season grasses like the bluegrass and fescue grass thrive better during fall, winter, and early spring. During summer, they tend to go dormant. Applying synthetic, nitrogen-rich fertilizers at this point could do your lawn a great deal of harm.

Hence, applying nitrogen is usually better during fall and spring. At those seasons, the grasses are usually more resilient and resistant.


“Enough” is usually just the right quantity to go with when carrying out any lawn care practice. And this isn’t any different when applying nitrogen to your lawn. Just because nitrogen is essential doesn’t mean “much” is necessarily beneficial to your lawn. Sticking to the right quantity is all that is need to have that beautiful and verdant lawn you dream of.