A lawn not only needs fertilizer but a proper fertilizing schedule as well.
Lush green lawns are rarely a product of mother nature. In most cases, they are created through careful planning, and proper nurturing, and lawn fertilization is arguably the most vital ingredient for that. Like humans and animals, grass needs an adequate supply of nutrients to thrive. With these essential nutrients lacking in most lawn soils, it becomes necessary to fertilize your yard now and again to support healthy grass growth.
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Unfortunately, most people often do not know which fertilizers they should use or when, how and how many times they should fertilize their lawns. Even more concerning is the fact that overusing the fertilizer can actually do more harm than good.
Most lawns only need to be fertilized twice or thrice per year. However, if your lawn soil is particularly poor, a full feeding is recommended every two to three months. Also, you want to fertilize your lawn when the grass is growing most rapidly.
That said, the frequency of lawn fertilization will change depending on the fertilizer, climate and the type of grass you have. So, let’s go ahead and explore this in a bit more detail.
How Often Can You Put Fertilizer On Your Lawn?
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Overfertilization can be as harmful to the lawn as under fertilization.
Even though applying fertilizer to the growing grass has several benefits, you do not want to overdo it. Most lawns can do fine with two or three feedings per year, though some lawns might need to be fed five or six times a year.
However, in no case should you over-fertilize your lawn. Excess fertilizer in the lawn soil can create a plethora of lawn problems. For instance, it can cause grass burns and promote weed growth. The result is an unsightly lawn with poor grass health.
To understand how often you should fertilize your grass and avoid over-fertilization, you will need to understand the requirements of your lawn soil, the type of grass you have and the fertilizer you use. The following factors are most critical when it comes to determining the frequency of lawn fertilization:
- Fertilizer Application Time
- Type Of The Fertilizer Being Used
- How Do You Put Fertilizer On Grass
- How Often Do You Water Your Lawn
We will discuss these points one by one in some detail below.
Fertilizer Application Time
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Every grass has its own ideal time for fertilization.
New grass benefits from fertilization whether it is seeded, sodded or sprigged. For planting grass seed in good soil, adding a bit of compost might be all you need to do. However, in less than ideal soils, you will need to add a starter fertilizer.
Starter fertilizers are specially designed to give the grass an early boost of nutrients at the start of its growth. They are based on a quick-release formula and contain higher nutrients, especially phosphorus, to help seeds sprout and form deep roots.
Following the initial application of starter fertilizer, you will need to further fertilize your lawn after about six to eight weeks and then two or three times more every six weeks. If your lawn is well established, fertilizing it each season is more than enough.
However, if you are establishing a new lawn, it will need many more fertilizer applications until it is fully established. The same is true for a grass that is not native to your area as it is under significant environmental stress.
On the other hand, the opposite is true for grasses that are local to your area. Lawns established with native grasses can usually get by with only fertilizing 1 to 2 times per year.
Apply Fertilizer When Grass Is Actively Growing
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Never fertilize the grass in its dormancy, not even once!
As a general rule, apply the bulk of the fertilizer during the active growth season. Depending on the variety of grass, active periods of growth will vary. Nonetheless, the aim of applying fertilizer to the grass during its active growth is to support its natural growth cycle.
It means that you are not forcing the grass to grow when it needs to be in survival mode or go dormant. Fertilizing grass during its dormancy is wasteful and encourages the growth of weeds in your yard.
Fertilizing Cool-Season Grasses
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Creeping bentgrass: cool-season specialty grass.
Cool-season grasses such as fescue grass, bentgrass and ryegrass grow the most in early spring or fall. So, you will need to fertilize the grass once in summer while mowing your lawn. And then again in fall, when temperatures drop.
Experts usually suggest waiting until labor day to fertilize the cool-season grasses. However, make sure that you do not fertilize your lawn too late. Fertilization of cool-season grasses should be completed at least six weeks before the first frost.
Fertilizing Warm-Season Grasses
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Bermuda grass: a perennial warm-season turfgrass.
Warm-season grasses such as centipede grass, zoysia grass and St. Augustine grass actively grow during the hot months of summer. So, the best time to fertilize warm-season grasses is in late spring, when the grass is getting ready to enter maximum growth.
You can fertilize the grass throughout the summer; however, avoid fertilizing your lawn too late. Moreover, ensure that you do not fertilize your lawn in the extreme heat. It can cause severe lawn burns, which will ruin your turf.
Fertilizing Across the Seasons
In addition to the type of grass, fertilizer requirements are also affected by climate and weather. Here’s a summary of how to fertilize your lawn in different seasons:
Fertilizing The Lawn In Spring
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Do not fertilize your lawn too early in the spring.
Both cool- and warm-season grasses are somewhat active during the spring. Therefore, fertilizing your lawn in the spring months could help boost the growth of your grass. However, even in spring, they must be fertilized at slightly different times.
In spring, fertilize the cool-season grasses when soil temperatures reach 55 degrees Fahrenheit and fertilize warm-season grass when soil temperatures reach around 65 degrees Fahrenheit.
Avoid fertilizing both cool- and warm-season grasses too early in the spring. It can promote weed development on your lawn. Also, if needed, you can fertilize the lawn again in April and May, six to eight weeks after the initial spring fertilization.
Fertilizing The Lawn In Summer
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Do not fertilize your lawn on extremely hot days of the summer.
Grass that is fed and fertilized well can survive the summer heat and dry conditions better. However, every type of grass does not need to be fertilized in the summer. For instance, cool-season grasses stay dormant in summer, so they don’t need to be fertilized.
The exceptions are cool-season grasses grown in cool-summer high-elevation areas. Here, you can feed the cool-season grasses, but we suggest you use less fertilizer. For the rest of the areas, wait until early fall and then fertilize your cool-season lawn.
On the other hand, summer is the most critical feeding time for warm-season grasses. You can apply the fertilizer once in June and then again a few weeks before the first expected frost. However, this time try using an organic fertilizer.
Fertilizing The Lawn In Fall
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Apply a winterizing fertilizer to your cool-season grass at the start of September.
Cool-season grasses grow most during the fall, so it is a time when they need as many nutrients as they can get. In areas with mildly cold winters, the cool-season grasses usually stay green throughout the winter; however, fall feeding is still recommended.
Whereas, in extremely cold regions, you should fertilize the cool-season grasses in late autumn. It will help the grass recover from the summer heat and prepare it for a strong spring comeback after the winter dormancy.
On the other hand, warm-season grasses slow down their growth in fall to prepare for the winter dormancy. So, they do not need extra nutrients at this time. That is why it is not recommended to fertilize warm-season grasses in the fall.
Fertilizing warm-season grasses during the fall puts the grass under stress. It is because you are forcing the grass to spend nutrients on growth when it should be storing nutrients for its winter dormancy.
Type Of The Fertilizer Being Used
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A natural solution to the fertilization requirements of your lawn.
In addition to the application time, the nature of the fertilizer used also affects the frequency of lawn fertilization. Broadly speaking, fertilizers are usually divided into two groups: synthetic fertilizers and organic fertilizers. However, you might also hear the terms slow-release fertilizer and quick-release fertilizer as well.
Let’s just quickly compare the properties of organic and synthetic fertilizers. Then we will discuss how and when you can use them in your yard.
|Organic Fertilizer||Synthetic Fertilizer|
|It is not readily available and can be costly.||They are cost-effective and readily available.|
|Because of their “raw” state, they need more effort to administer, especially across a big area.||Because they come in the shape of pellets or granules, they are simple to use, even in large areas.|
|In most cases, adding too much organic fertilizer to your lawn will not hurt it.||Lawn burns are frequent as a result of over-application or fertilizer spillages.|
|Nutrient concentration varies from batch to batch.||Every bag’s nutrient concentration is the same.|
|Beneficial for the lawn ecosystem.||It has minimalistic benefits to the lawn ecosystem.|
|Leaching or runoff is little, if at all.||Leaching can cause a considerable amount of fertilizer to be lost.|
|Nutrients will be released at a rate that plants can use. Thus, fewer applications will be needed.||Nutrients are readily available but only for a limited time. So, frequent applications will be needed.|
It is clear from the table above that synthetic fertilizers can get you the results much quicker; however, they are not a good solution for long-term sustainability. On the other hand, organic fertilizers are sustainable but slow in action.
So, we suggest you start off your lawn using a synthetic starter fertilizer and then shift to organic options when the lawn is well-established.
What Are The Three Ingredients In Lawn Fertilizer?
A lawn fertilizer contains three main elements: nitrogen, phosphorus and potassium. The ratio in which these elements are mixed is known as the NPK ratio. Grass requires fertilizers with different NPK ratios at different stages of its lifecycle.
When To Use Nitrogen Fertilizer?
Nitrogen increases the grass growth and makes your lawn look more green. You can use nitrogen fertilizer on your lawn twice a year. For best results, apply the nitrogen fertilizer in the spring and fall for cool-season grasses and throughout the summer for warm-season grasses.
When To Use Phosphorus Fertilizer?
Phosphorus promotes root development and should be used, especially when establishing a new lawn. Phosphorus stays available to the grass for at least four months after application. So, for cool-season grasses, apply it in fall or spring. Whereas for warm-season grasses, use phosphorus fertilizer in late spring or summer.
When To Use Potassium Fertilizer?
Potassium is a nutrient that strengthens the grass and increases its resilience. So, it should be used when the grass is under stress. For cool-season grasses, the summer heat is a stressful period. In contrast, winters are a period of great stress for warm-season grasses.
How Do You Put Fertilizer On Grass?
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Liquid fertilizers are usually hard to handle and apply.
Lawn fertilizers come in different forms, i.e., liquid, spray, granules, pellets etc. Depending on its form, the process of the application of fertilizer will vary. Typically granular fertilizers are easier to handle and apply. Also, granular fertilizers have a lower risk of over- or under-fertilization, which saves on cost.
With liquid fertilizers, experts usually recommend hiring a lawn care professional. It is because they are difficult to measure and apply uniformly over the lawn. Regardless of the form of the fertilizer, it is highly recommended not to apply fertilizer when there is expected rain.
It can cause significant loss of nutrients with water runoff or may cause the fertilizer to penetrate deep away from the grassroots reach.
How Often Do You Water Your Lawn?
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With overwatering comes the risk of water, soil and nutrient runoff.
Another thing that could affect the fertilization requirement is how often you water your lawn. Both under- and over-watering the lawn can be the culprit behind the excessive need for lawn fertilization. It is because when you overwater your lawn, excess water can make puddles or runoff from the surface of your lawn.
This results in nutrient loss and nutrients accumulating in spots over the lawn surface, which increases the need for lawn fertilization now and again. Similarly, nutrients won’t reach the grass if the lawn is underwatered. They will break down and eventually become useless for staying on the surface exposed to environmental elements.
So, make sure that you water your lawn adequately after fertilization. It will not only increase fertilizer efficacy but will lessen the need for frequent fertilizer application as well.
Lawns with good quality soil will do just fine with two or three fertilizer applications per year. However, if the lawn soil is particularly poor more fertilizer applications will be needed. That said, the frequency with which you need to fertilize your lawn will also vary depending on the type of lawn fertilizer, timing of fertilization and your lawn care efforts.
Frequently Asked Questions
How often should I fertilize the lawn?
Most lawns only need to be fertilized twice or thrice a year, and lawns with particularly poor soil need to be fed five or six times a year. Anything more than that is too much, especially when you see signs of over-fertilization.
Can you over-fertilize grass?
Using too much fertilizer can ruin soil chemistry and even kill the grass. So, always only use the required and recommended amount.
Can I fertilize my lawn every two weeks?
If you want to avoid over-fertilizing your lawn, using a fertilizer every two weeks is not recommended. It can cause grass burns and ruin soil chemistry.
Should I fertilize grass in the morning or evening?
Late afternoon and early evening is usually the best time to fertilize your lawn. That said, do not fertilize your lawn when it is too sunny or too hot, it can cause grass burns. Also, do not fertilize your lawn when there is heavy rain expected.
Do you water grass after fertilization?
It depends on the physical form of the fertilizer. If you are using a granular fertilizer, you will need to water the grass to help the granules dissolve and absorb into the soil. However, if you are using a liquid fertilizer, watering your lawn can wash off the fertilizer from the grass.
Sources for Further Reading
How often should I fertilize my lawn? – Iowa State University Extension and Outreach
Fertilizing Schedule for Home Lawns – University of Illinois Extension
Lawn care calendar – University of Minnesota Extension