How Long Does Fertilizer Take to Work?

Growing a lush, green lawn doesn’t happen overnight. You’ve got to choose the right fertilizer for your grass and know how to apply it to get a healthy lawn your neighbors will envy. But how long does lawn fertilizer take to work? Depending on what type of fertilizer you choose, it may take 2 days — or 2 weeks. Let’s get to the root of how long lawn fertilization takes to work!

The Importance of Fertilizing Grass

Almost everyone knows that grass fertilizers promote healthy, green grass. People often think of lawn fertilizer as food for grass that helps individual grass blades grow faster. But lawn fertilizer does more for grass than just deliver nourishment and speed up growth.

1. Longer Roots

A properly applied fertilizer treatment will help your grass roots grow deep. A healthy root system with long roots helps your lawn survive intense heat and drought. They will also make your lawn more resilient in areas with heavy foot traffic.

2. Weed Control

Grass fertilizer doesn’t just feed your grass — it’s known to reduce weeds. How? Fertilizer improves soil conditions by making the soil more phosphorus, potassium, and nitrogen-rich — all all the ingredients that most weeds can’t stand! Some fertilizers even act as pre-emergents, stopping the germination process before it starts. So if you’re looking for better lawn weed control, talk to your local lawn care professional about fertilizer types and timeline!

3. Lawn Aeration

Fertilizers, especially organic ones, improve soil structure by adding organic matter, which enhances water retention and lawn aeration. This also encourages beneficial microbial activity in the soil, leading to healthier soil and a healthier lawn.

How Long Does It Take Lawn Fertilizer to Work?

How long it takes lawn fertilizer to work depends on whether you use organic fertilizers or synthetic fertilizers.

Lawn fertilizers encourage new grass growth by providing essential nutrients your lawn needs to flourish — but sometimes, they can hurt your grass when incorrectly applied. Quick-release fertilizers work well but may lead to fertilizer burn. Slow-release fertilizers require patience but prove much safer to use. Below, find the estimated time it takes for the most popular lawn fertilizers to work.

How Long Does Fertilizer Take to Work: Quick-Release Synthetic

Quick-release synthetic fertilizers work as soon as they hit the soil. They serve as the perfect solution when preparing for a backyard birthday party because they will make your grass greener and promote new growth in 24 to 48 hours.

How Long Does Fertilizer Take to Work: Quick-Release Organic

Quick-release organic fertilizers work within 48 to 72 hours. These fertilizers are made from natural sources, such as fish emulsion, seaweed, or poultry manure, and provide a more environmentally friendly option for lawn care.

How Long Does Fertilizer Take to Work: Slow-Release Synthetic

Slow-release fertilizers work slowly but deliver long-lasting results, promoting root growth for new lawns. They provide a steady, gradual supply of nutrients over an extended period, typically six to eight weeks. You’ll start to notice a difference in grass growth around five days after application.

How Long Does Fertilizer Take to Work: Slow-Release Organic

Slow-release organic fertilizer will show results within a month. This process can take several weeks to a month, with the full benefits often becoming apparent throughout the growing season. While you may not see immediate results, the gradual improvement in lawn health and soil quality will ultimately lead to a greener, more sustainable landscape.

What Is Quick-Release Fertilizer?

Quick-release fertilizer produces positive results within a matter of days, not weeks. Also known as fast-release fertilizer, it provides nutrients that a lawn can easily absorb.

Most manufacturers make quick-release fertilizer in a liquid fertilizer form because the nutrients easily seep into the soil where the roots can absorb them. Lawn care professionals dilute this type of fertilizer in water before application to prevent fertilizer burn.

Quick-release synthetic fertilizers often contain:

• Ammonium nitrate
• Potassium phosphate
• Calcium nitrate
• Potassium nitrate
• Ammonium sulfate

Quick-release organic fertilizers include:

• Fish emulsion
• Seaweed
• Bat guano
• Poultry manure

What Is Slow-Release Fertilizer?

Slow-release fertilizer breaks down slowly to feed your lawn over an extended period. Also called controlled-release fertilizer, it takes extra time to see results, but the results are long-lasting. Many lawn care experts prefer slow-release fertilizers because they are more efficient and less likely to cause lawn burn.

Synthetic slow-release fertilizers often contain:

• Isobutylidene diurea (IBDU)
• Crotonylidene diurea (CDU)
• Urea-formaldehyde (UF)

Organic slow-release fertilizers include:

• Kelp meal
• Cow and horse manure
• Blood meal
• Vermicast
• Bone meal
• Compost
• Cottonseed meal

Applying Different Types of Fertilizers

Should you mix fertilizers or switch after your lawn’s first treatment? In cases that involve new grass seed, a combination of fertilizers may serve your lawn the best. That way, if you forget to apply fast-release fertilizer, the slow-release product will cover you.

Some manufacturers even produce granular fertilizer that contains a mix of both kinds of fertilizer. An experienced lawn care professional can tell you which type of fertilizer will help your lawn the most.

Best Time to Fertilize Grass

The best time to use fertilizers depends on the fertilizer and your grass type. For example, synthetic fertilizer should be applied to wet grass around dusk on a day with cold weather. That way, you reduce your risk of lawn burn. Synthetic granular fertilizer can burn dry grass on a hot day.

Your annual fertilization schedule will vary based on lawn type, location, and fertilizer preference. Most professionals apply granular fertilizer in early spring, late spring, early fall, and early winter.

To learn about your lawn fertilization schedule based on your region, find your local Heroes Lawn Care provider.

Fertilizer Re-Application Schedules

A lawn begins to absorb grass fertilizer almost immediately — and you may see results quicker than you think. But how long does fertilizer take to work and fully be absorbed? When do you need another lawn fertilizer application? Let’s find out!

When Should Fast-Release Fertilizer Get Re-Applied?

It takes two to four weeks for a lawn to fully absorb fast-release fertilizer. As a result, lawn care professionals must reapply fast-release synthetic fertilizers more often than other lawn fertilizers. Applying fertilizer of this type too frequently may result in fertilizer burn. Speak with your local lawn care and landscaping professional about your lawn fertilization schedule.

When Should Slow-Release Fertilizer Get Re-Applied?

It takes six to eight weeks for a lawn to fully absorb controlled-release fertilizer. These types of lawn fertilizer break down slowly to feed your grass over an extended period. In some cases, it may even take more than eight weeks for your lawn to fully absorb slow-release fertilizers. Before re-treating your lawn, speak with your local lawn care professional about your fertilizer treatments.

FAQ: How Long Does Fertilizer Take to Work?

How Fast Will Lawn Fertilizer Turn My Grass Green?

If you want green grass, you need to know when you can expect to see the results you seek. Granular fertilizer made with organic materials will start turning your grass green about two to five days after you apply fertilizer. However, you will not see the full effect on the color of your grass until about seven days later.

Quick-release products are the right fertilizer to use if you need your grass to turn green within a day or two. Remember that the initial results will make your grass greener in patches. A few weeks later, the color of your grass will even out.

Should I water my lawn after fertilizing?

You should water your lawn 24 hours after fertilizing it to allow the fertilizer to settle. When you water your grass, drench it to activate all the fertilizer. Soaking your lawn will also help the uptake of nutrients into your soil. Giving your lawn little more than a quick spritz will prove ineffective at activating all of your fertilizer.

How many minutes should I water my lawn after fertilizing?

You should water your lawn for 45 minutes to one hour after fertilizing. This rule of thumb does not account for your sprinkler system, climate zone, or lawn type. In general, you want to make the soil moist to three inches deep.

Should you mow before or after fertilizer?

You should mow immediately before fertilizer. This strategy will allow the fertilizer to reach the soil easily. Plus, after you apply fertilizer and water your lawn, you will not need to mow your lawn for at least another week.

Can I fertilize my lawn every 2 weeks?

You can not fertilize your lawn every two weeks and expect optimal results. Fertilizing every two weeks may result in lawn burn, excess lawn waste, polluted groundwater, and toxic algae growth.

Should I Put Down Fertilizer at Night or Morning?

You should put down fertilizer as directed by the manufacturer’s instructions. Your local lawn care expert will apply the fertilizer at the recommended rates using the best possible methods. In general, early morning or late evening are the best times to put down fertilizer. Your lawn care professional will water your lawn after application to spread the fertilizer more evenly and prevent burning.

Believe Your Eyes – It’s Because You Fertilized!

You’ll be surprised at how fast the right type of fertilizer can work wonders on your lawn! Of all the different fertilizers on the market, only organic granular fertilizers offer the unique combination of easy application and a controlled release. If you think your new lawn may need organic granular fertilizer, find a local Heroes Lawn Care near you to discuss which kind of fertilizer is right for your grass.