Should You Mow Before Fertilizing Your Lawn?

Man cutting grass with gasoline lawn mower on the backyard, cropped image with no face

Mowing at the wrong time could jeopardize your fertilizer application (and your turf). So, should you mow before fertilizing? Absolutely, as long as you mow your lawn one or two days before applying the fertilizer.

The worst time to mow when applying fertilizer is immediately before and immediately after fertilizing. Mow right before fertilizing, and you risk fertilizer burn. Mow right after fertilizing, and you’ll scatter the fertilizer.  

Mowing a couple of days before fertilizing helps maximize your fertilizer’s effectiveness. Other ways to prepare your lawn for fertilizer include aeration, dethatching, and watering, which we’ll cover in more detail below.

Why You Should Mow Before Fertilizing

Mowing your lawn in preparation for a fertilizer application clears away debris and maximizes the effectiveness of your fertilizer. If you don’t mow, or worse, mow at the wrong time, you risk consequences like fertilizer burn. 

Here are some of the benefits of proper lawn preparation, as well as the consequences of doing it wrong:

Benefits of Mowing Before Fertilizing

lawn mowing by lawn mower
Photo Credit: Prasannanossam3 / Wikimedia Commons / CC BY-SA 4.0

Mowing before fertilizing carries several benefits for your lawn. Namely, the fertilizer distributes more evenly and you reduce the risk of harmful effects like nitrogen burn.

  • Increased Effectiveness: The main benefit to mowing your lawn before you fertilize is increasing the effectiveness of the fertilizer. Mowing removes lawn debris and overgrowth that would otherwise block fertilizer reaching the soil.
  • Even Distribution: Another benefit is your fertilizer distributing more evenly. Buildup and lawn debris isn’t uniform, so your fertilizer may reach some parts of your soil more than others. Uneven fertilizer distribution can result in patchy growth.
  • Avoiding Nitrogen Burn: Finally, mowing your lawn a couple of days before fertilizing decreases the chance of nitrogen burn, also called fertilizer burn. Fertilizer burn occurs when your lawn receives excess nitrogen and salts, which leeches moisture from the grass and dries it out. This creates a brown spot where the grass is either dead or dying.

For more information on lawn mowing, read here: Lawn Mowing Tips: How to Mow a Lawn the Right Way

Consequences of Not Mowing Before Fertilizing

The consequences of not mowing before you fertilize your lawn are roughly the inverse of its benefits. Your fertilizer will be less effective, you may see patchy growth, and grass has  an increased chance of nitrogen burn.

  • Decreased Effectiveness: Namely, the vegetation gets in the way of the fertilizer, making it less effective. Since your fertilizer won’t be able to reach the soil as quickly or easily, you may wind up wasting a good portion of the fertilizer.
  • Patchy Growth: Since the buildup is impeding the fertilizer on its way to the soil, parts of your lawn will get nutrients before the rest. The end result is patchy, uneven growth.
  • Nitrogen Burn: Not mowing also puts grass at a greater risk of nitrogen burn since the fertilizer can get stuck in the overgrowth and debris. Fertilizer is meant for the soil, not the plant, so all those nutrients sitting on your grass blades can easily lead to fertilizer burn.

For more information on fertilizer burn, read here: What is Fertilizer Burn?

Best (And Worst) Time to Mow and Fertilize Your Lawn

Gloved hands holding fertilizer above a bag placed on a lawn
Photo Credit: ronstik / Shutterstock

So, how long after mowing should you wait to apply fertilizer? The best time to mow your lawn before fertilizing is a few days beforehand, while the worst time to mow is immediately after an application. 

Best: Mowing a Few Days Before Fertilizing

The best timing to mow your lawn in preparation for a fertilizer application is 24 hours to a few days beforehand. Waiting a day or two to fertilize gives your grass time to recover from the trauma of being cut. Your lawn is stressed in the time following a mow, and the additional stress of the fertilizer can easily lead to negative effects.

Also, if you leave your grass clippings on the lawn, waiting to fertilize gives them time to break down before application.

Worst: Mowing Immediately Before or After Fertilizing

One of the worst times to mow your lawn is immediately before fertilizing. Mowing is traumatic for grass and leads to stress. Fertilizer will add additional stress that your lawn does not need. In the time immediately following a mow, your lawn is much more susceptible to fertilizer burn.

The worst time to mow the lawn, however, is immediately after fertilizing. Firstly, you have to water in fertilizer to make it effective. If you mow afterward, you’ll be mowing wet grass, which is never advised. Mowing while your lawn is wet results in a ragged, awful-looking patchy cut.

For more information about mowing wet lawns, read here: Why Mowing a Lawn When Wet is (Usually) Bad

In addition, mowing will spread the fertilizer around your lawn, which causes uneven application. This will make your lawn even more patchy and uneven, and the stronger concentrations of nutrients and salts in certain patches can cause, you guessed it, fertilizer burn.

Can You Mow and Fertilize on the Same Day?

A lawn mower on a lawn
Photo Credit: Horticulture / Adobe Stock

Yes, you can mow your lawn and fertilize it on the same day. However, it’s not as ideal as waiting a day or two in between. 

If you choose to mow and fertilize on the same day, wait a few hours after mowing to reduce the risk of fertilizer burn. If you leave your grass clippings on your lawn, ensure they’re spread evenly, or else your fertilizer may not apply evenly.

For more information on mowing and fertilizer, read here: Can I Mow and Fertilize on the Same Day?

Other Ways to Prepare Your Lawn Before Fertilization

Man watering green lawn, close-up with no face
Photo Credit: rh2010 / Adobe Stock Free / License

Of course, mowing is just one aspect of preparing your lawn for a fertilizer treatment. For best results, there are a few other steps you should take to prep your lawn for fertilization:

  • Soil Test:  Perform a soil test before applying any kind of fertilizer. A soil test will tell you what nutrients your soil has and in what amounts. Once you know that, you can choose the right fertilizer, one that has more of what your soil needs and less of what it has in abundance.
  • Watering: Water your lawn a day or two before fertilizing it so that it’s still slightly moist when you apply the fertilizer, which will help the nutrients move in the soil.
  • Weed Control: Clear away any weeds you can find in your lawn before a fertilizer treatment. If you don’t, you may wind up feeding the weeds instead of your lawn. Grassy weeds in particular have very similar nutritional requirements to turfgrass.
  • Pest Control: This is an optional step, but it can be a very important one. Fertilizer attracts insects, so applying a preventative pesticide can help keep creepy-crawlies away from your lawn.
  • Dethatching: While this is an optional step, a day or two prior to a fertilizer application is an excellent time for dethatching your lawn. Thatch can impede fertilizer from penetrating your soil. Dethatching gives the fertilizer a clear path and helps it do its job quicker. For more information, check out our article on When and How to Dethatch Your Lawn
  • Aerating: Just like dethatching, aeration is an optional step. But also just like dethatching, aerating can be a great help to your lawn before fertilizing. Aeration reduces soil compaction, which makes it easier for nutrients from fertilizer to travel in your soil. For more information on aeration, read our article on How to Aerate a Lawn.

FAQ About Mowing and Fertilization

Do I need to mow my lawn differently than usual in preparation for fertilizer?

No. Mow your lawn as normal when preparing for a fertilizer application.

How high should I mow my lawn?

The ideal height for a lawn will vary depending on your grass type. However, a good rule of thumb is to never take off more than one third of the grass’ total height. For example, if your grass blades are three inches tall, don’t mow your lawn shorter than two inches.

Can I fertilize my lawn before dethatching?

No. You shouldn’t dethatch after fertilizing your lawn since you’ll wind up wasting a good portion of the fertilizer.

Find a Lawn Guru Today

Mowing before fertilizing your lawn is an important step in lawn care. Always properly prepare your lawn before applying fertilizer. If you need help with your lawn, contact lawn care professionals near you. They can mow your grass and apply fertilizer for you so that you have more time to enjoy your day.

Main Image Credit: rh2010 / Adobe Stock Free / License

Austin Geiger

Austin Geiger

Austin Geiger is a lover of all things nature. He enjoys writing comprehensive, easy-to-swallow articles about pest management solutions, landscaping tips, and ways for people to help their local pollinators.