fertilizer time to work

How Long Does Lawn Fertilizer Take to Work?

There are many important nutrients your lawn soil contains that plants and grass need to grow and thrive. However, it doesn’t contain everything to keep your plants and grass healthy and green.

That’s why you need to use fertilizer, which contains important nutrients, such as nitrogen, phosphorus, and potassium, and works as food for your lawn.

But the time fertilizer takes to work depends on several factors, such as the type of fertilizer, soil’s moisture level, and outside temperature. For example, if you use a quick-release fertilizer, it’ll work more quickly than slow-release fertilizer.

In this article, we’ll discuss these factors in detail to help you understand how long lawn fertilizer takes to work.

How Long Lawn Fertilizer Takes to Work

There are two main types of fertilizers, including quick-release and slow-release.

Quick-release fertilizers work immediately as soon as you apply them, but it will take about two days to a week to turn your lawn grass green evenly.

Whereas slow-release fertilizers take a long time to dissolve. They can start turning your lawn grass green within five to 10 days but can take up to 12 weeks to fully green up the lawn.  

Let’s discuss different factors, including the grass fertilizer type, that affects the time fertilizers take to work.

Moisture in Lawn Soil

The only way plants and grass on your lawn can use fertilizer is if there’s water/moisture availability. It’ll allow the nutrients present in fertilizer to move around easily and reach plants.

If you use liquid fertilizer, it’ll reach plants and grass as it itself contains moisture. However, the moisture-liquid fertilizer won’t be enough if your lawn soil usually remains dry.

Additionally, dry fertilizer will need a lot of moisture to properly dissolve into the soil and reach plants and grassroots to supply the essential nutrients.

If you water your lawn within a day of the fertilizer application and add about one to two inches of water on the lawn every week, the fertilizer will work quickly.

Whereas, fertilizer will take more time to work on a lawn if it has less moisture. If there’s no moisture, fertilizer will not work and increase the risk of fertilizer burns.


Generally, the higher the temperature, the faster the fertilizer will work. It happens because most fertilizers release nitrogen content and other nutrients faster at high temperatures. So, if your lawn receives full sun, you can expect your fertilizer to work faster.

Time of the Year

The time of the year is another important factor that affects the time lawn fertilizers take to work. Most commonly, fertilizers are applied to lawns during the growing season because grass and plants need more nutrients than at any other time of the year. If you spread fertilizer during the growing season, it’ll work quickly.

Type of Lawn Fertilizer

The fertilizer type is the biggest factor affecting the time fertilizers take to work. As mentioned, fertilizers are divided into two types: quick-release and slow-release. Let’s discuss these types in detail to understand how long they take to work.

Quick-Release Fertilizer

Most quick-release fertilizers come in the form of liquids. They can start working as soon as you apply them on your lawn and provide you with results within a few days. Keep in mind that quick-release fertilizers further have subtypes, such as ready-to-use and powdered fertilizers.

Ready-to-use fertilizers are great for beginners, and they’re fast-acting, but powdered products can take a few days longer to work. Although you don’t spread the powder on your lawn as you need to mix these fertilizers with water, they’re usually gentler in composition.

Some synthetic granular fertilizers available in the market come with quick-release compositions as well. They have readily available nutrients that your plants and grass can start absorbing as soon as you apply them.

These fertilizers can also provide you with expected results within a few days to a couple of weeks. If you need a fertilizer that generates results quickly, we recommend you buy a product that totes “fast-acting” or “instant results.”

Important Note: Quick-release fertilizers will suit you best if your lawn has unhealthy and weak grass/plants that need immediate attention.

Slow-Release Fertilizer

Most slow-release fertilizers come in the form of granules that you spread across the lawn using some sort of spreader. These fertilizers aren’t used for quick results; you’ll need to wait for two to three weeks before you start seeing results.

You should use a slow-release fertilizer if you already have a healthy lawn that only needs assistance for healthy grass growth in the growing season. You can purchase organic granular fertilizer from the market if you don't want to use synthetic fertilizers.

You don’t necessarily need to purchase a slow-release fertilizer from the market, as you can make one yourself at home. If you manage a compost heap, you can spread it over your lawn as a slow-release organic fertilizer.

You can also spread grass clipping on your yard as it’ll slowly release important nutrients such as nitrogen to help your lawn grow.

Why Slow-Release Fertilizers Take Longer Time to Work

In simple words, slow-release fertilizers take a long time to work because the nutrients they contain aren’t as mobile as quick-release fertilizers. They can’t move freely to reach the roots of plants and grass and must be processed/decomposed timelily.

Over time the decomposition of slow-release fertilizers allows them to release their nutrients into the soil. The exact time that a particular product will need to decompose and work fully will depend on the materials it contains.

As the fertilizer breaks down and starts to work, you’ll notice that your grass has begun turning greener. After that, a surge in growth will take place.

How Long Do Fertilizers Last in the Soil?

Generally, slow-release fertilizers can last in your lawn soil for up to three months, and quick-release fertilizers can last for around two to three weeks. So, you might only need one or two applications of quick-release fertilizer during the growing season.

On the other hand, you’ll need to spread quick-release fertilizer multiple times (after two to three weeks) on your lawn in a single season to help grow your plants and grass.

Remember that you’ll need to use the fertilizer correctly to reap its benefits. If you under-fertilize your lawn, your plants and grass will experience a deficiency of certain nutrients and won’t have healthy growth.

Whereas, if you apply more fertilizer than required, you’ll increase the risk of fertilizer burns, resulting in dying grass and plants. Therefore, read the instructions on the product’s packaging carefully to find the right amount of fertilizer that your lawn needs.

Final Words

Different types of fertilizers can take different amounts of time to work. If you have weak and unhealthy grass/plants, you should use quick-release fertilizers as they work quickly. 

However, you can use a slow-release fertilizer if you have a healthy lawn and want to help it grow and improve its beauty during the growing season.

Leave a Reply

Your email address will not be published. Required fields are marked *