If your lawn is looking sickly, you’ve probably thought about adding fertilizer. In this article, we’ll discuss what fertilizer is, when to apply it, and a simple, step-by-step process for maximum results. 

    What is Grass Fertilizer?

    Pile of leaves
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    Got grass clippings? You’ve got fertilizer. 

    What about manure, humus, or plant matter? Those work, too.

    Today most homeowners choose synthetic over natural fertilizers to beautiful their lawns, but the concept is the same. Fertilizers are simply organic or synthetic materials that provide nutrients to the soil. 

    Those nutrients, along with carbon dioxide, water, and sun, provide the grass with the building blocks for growth and green-up. Turf managers and homeowners today turn to these synthetic fertilizers for professional-level results.

    Why You Should Fertilize Your Lawn

    Fertilizers with a spray applicator
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    Most of us want to fertilize for aesthetic reasons — so that our grass looks better. Routine chores such as overseeding, aerating, fertilizing, and deep watering are the best ways to achieve this.  

    How does grass fertilizer work? Weeds are crowded out, root systems grow deep, and the lawn can better handle environmental stresses, leaving it a more beautiful and healthy lawn.

    When Should You Fertilize Your Lawn?

    When it comes to fertilizing your lawn, timing is everything. The answer to the “when” question depends on where you live, but there is one general rule: Don’t feed the lawn during periods of dormancy.

    If you live in the northern part of the country, you have cool season grass. If you live in the southern part of the country, you have warm season grass. If you live in the mid-Atlantic region, you may have either type of grass. 

    What’s the difference between these grasses? Warm season grasses have one growth period, which peaks in summer. Cool season grasses have a growth period in the spring and another, smaller growth phase in the fall.

    How often should you fertilize your yard?

    How often you want to fertilize is up to you. Your grass type is also a factor, but twice per year is standard for most grass types. 

    If you want to fertilize twice per year:

    Cool Season Grass: perennial ryegrass, fescue, Kentucky bluegrassWarm Season Grass: St. Augustine, centipede, bahia, bermuda
    Apply a heavier application in the fallLate spring, about two weeks after it starts to green
    Apply a lighter application in early springLate summer, once temperatures begin to decline

    If you want to fertilize throughout the season, a general recommendation is to start in the spring and continue every four to eight weeks for a total of four to six fertilizer applications.

    If you want local advice, check with your county Extension agent or go to your state’s Extension Office website to find lawn fertilizer schedules such as these lawn calendars for Georgia. Lawn calendars advise when to put down the first application in the spring and how long to continue based on your climate and grass. 

    Lawn calendars give fertilizer recommendations as well, which is helpful if you haven’t done a soil test.

    Most lawn calendars recommend waiting until the soil temperature (not air temperature) reaches a certain level before you start applying fertilizer in the spring. Use a soil thermometer or plug in your address to a soil temperature map to determine how hot or cold your soil is. 

    How to fertilize your yard in 7 steps

    Note: These directions apply to established lawns.

    1. Get a soil test

    close=up of a handful of dirt in someone's hand
    Photo Credit: Pixabay

    Soil tests are like bloodwork for your lawn. Depending on the test, it may list the type of soil, the level of your macronutrients, and the soil pH, among other things. Contact your local Cooperative Extension Service to send the soil sample to a lab, or buy an at-home test. 

    2. Measure your lawn

    Man measuring his yard
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    While you’re waiting on your soil test results, measure your lawn. Why? You need to know how many square feet need to be fertilized. You can measure your lawn a few ways:

    1. Use a measuring wheel
    2. Use an online tool such as MyYardSize.com
    3. Get out a tape measure or count the number of paces it takes you to walk the mowable space.

    Calculating your yard size is important when you are setting the rate of application on the fertilizer spreader.

    3. Mow your grass

    Lawn mower sitting in the middle of a mowed lawn
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    Put the bag on the mower to bag the clippings (just this once). In most cases, you want to leave the mulched clippings on the lawn since it acts as a natural lawn fertilizer. In this case, bag them. It helps the fertilizer to have better contact with the soil.

    4. Buy lawn fertilizer

    bags of fertilizer on a driveway
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    Choose your lawn fertilizer based on the results of your soil test. If you have not done a soil test, check your Extension Service’s lawn maintenance calendar for general fertilizer guidelines. 

    5. Apply the fertilizer

    hand-held fertilizer sprayer being applied
    Photo Credit: Jerry Norbury / Flickr / CC BY-ND 2.0

    Read the label on your fertilizer for application rates. Common ways to disperse your fertilizer include hand-held spreaders, drop spreaders, and rotary spreaders.

    6. Water your fertilized grass

    close-up of a sprinkler head watering the lawn
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    How soon you should water your grass after fertilization depends on the fertilizer. If your fertilizer does not include a weed control element, it’s best to water your grass right after application. Check the product label for instructions. 

    From there, resume your normal watering schedule. Most experts recommend watering deeply once per week. If there is heat stress or rain, adjust your watering schedule accordingly.

    One final tip: Keep everyone off the grass for a full 24 hours after you fertilize. 

    7. Enjoy your fertilized yard

    Woman relaxing in the grass
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    After you apply a nitrogen fertilizer, you’ll see results relatively quickly. 

    Many products include quick-release and slow-release nitrogen. The quick-release fertilizer results in a quick uptake of nitrogen and a fast green-up. The slow-release nitrogen continues to feed the lawn slowly over time. 

    According to a Purdue Extension bulletin, if your fertilizer includes a quick-release source of nitrogen, expect a greening response in as quickly as a few days or as long as 10 days.

    FAQ About Lawn Fertilizers

    1. What are those numbers at the bottom of the fertilizer bag?

    If you see something like “10-10-10,” these are the NPK values, or Nitrogen-Phosphorus-Potassium values, in the mix. So, this bag has 10% nitrogen, 10% phosphorus, and 10% potassium, along with other nutrients.

    If you’re considering fertilizing your lawn, know that granular and liquid fertilizers work equally well, but most experts recommend a granular type with quick- and slow-release fertilizers. This allows for a fast green-up and then a steady, continual release over several weeks. 

    Liquid fertilizers are more often used to supplement granular varieties throughout the growing season. Most liquid fertilizers come with a hose attachment for ease of application. These foliar applications give a short-term boost and are not recommended as a standalone fertilizer.

    2. What are some natural or organic fertilizers for your lawn?

    If you’re considering organic fertilizer for your lawn, try these alternatives:

    • Blood meal: Nitrogen (N)
    • Bone meal: Phosphorus (P) 
    • Potash or kelp meal: Potassium (K)

    How can you be careful when applying fertilizer?

    safety glasses being held by someone
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    Lawn chores can pose health or environmental hazards if you’re not mindful of the risks. Keep these things in mind before you fertilize.

    ✅ Wear safety glasses, gloves, and long-sleeve shirts and pants. 

    ✅ Follow the guidelines on the fertilizer label. (Don’t neglect to read labels for natural or organic products. These need to be applied according to the directions just as with synthetic products.)

    ✅ Avoid windy days when fertilizing your lawn and watch for runoff. Be especially careful if the grass being fertilized is near a drain or waterway. 

    ✅ Know your local laws concerning fertilizer use. (See Tips for Fertilizing your Lawn below.)

    ✅ Keep your pets and kids away from the fertilized lawn. Be sure (again) to read the instructions to see if there is a stated re-entry time for little paws and feet.

    ✅ Store any fertilizer where it is out of the sun and out of reach of children.

    ✅ Have on hand the emergency numbers for poison control and your vet just in case.

    Tips for fertilizing your lawn

    Sweep fertilizer off the hard surfaces after you apply it to the lawn. This prevents stains on the masonry and runoff. 

    • Buy only as much fertilizer as you can use within one season. 
    • Applying too much fertilizer is not a good thing. You only want to apply what you need based on your soil test and the package instructions. 
    • Know your local ordinances: Some states, counties, or cities have fertilizer regulations in place. Certain cities in Florida, for example, have blackout periods in the summer months when homeowners and professionals may not apply fertilizers to residential lawns. Other restrictions may include fertilizer-free zones, mandates on the percentage of slow-release vs. fast-acting nitrogen in the products, or limits on the percentage of a particular nutrient per bag.

    Fertilizer fun fact

    Han holding a clump of fresh cut grass clippings
    Photo Credit: Matthew Bellemare / Flickr / CC BY-SA 2.0

    According to the University of Minnesota Extension Service, one year’s worth of mulched grass clippings provides as many nutrients to the lawn as one fertilizer treatment. 

    Fertilizing for a greener lawn

    Lawn with bare spots
    Photo Credit: Brian Hart / Flickr / CC BY-SA 2.0

    Fertilizing the lawn is relatively quick and easy and has a fast return on your investment — you should see results in as little as a few days. Test the soil, measure the lawn, mow, fertilize, and water — that’s it. 

    Lawn fertilization is easy enough to do as a DIY project (as long as you follow the product directions), but if you’d rather not spend your time spraying or spreading fertilizer, we can help you to find a lawn care professional near you.

    However you decide to fertilize your grass, by feeding your lawn the nutrients it needs when it needs it, you’re sure to have a greener, healthier lawn throughout the growing season.

    Main Photo Credit: Mark Lee / Flickr / CC BY 2.0