You’re Probably Fertilizing Your Lawn Wrong—Here’s How to Fix It This Spring
When grass starts to wake up from winter dormancy and grow again, it’s not only a sign that spring is in full swing, but that it's time to fertilize your lawn. Taking the time to feed fertilizer to your lawn during its growing months helps keep it healthy and strong.
”Lawn fertilizer delivers essential nutrients required for vigorous growth and a lush, thick appearance,” says Brian Feldman, senior director of technical operations at TruGreen. “This is particularly vital for residential lawns where soil typically lacks adequate nutrient levels for ideal plant development.”
While you don’t need a green thumb to conquer the task of fertilizing, you do need to know what type is best for your grass and how to apply it so you don’t end up with a worse lawn than when you started. “Applying fertilizer during extreme heat can burn your lawn, and applying products too early when the ground is still frozen won’t be effective. For most homeowners, the focus should be on applying the right products at the right time of year,” says Cameron Brown, merchant of seed and fertilizers at The Home Depot.
Keep reading this lawn fertilizer guide to learn how to choose the right fertilizer, how to apply it correctly, lawn fertilizing tips, when to fertilize lawns, and mistakes to avoid.
What Lawn Fertilizer Does
In order to achieve a lush green lawn, your grass needs 17 essential elements. Some, like carbon, hydrogen, and oxygen, can be absorbed from the air, but others are supplied through fertilizer. Specifically, grass is hungry for three main nutrients: nitrogen, phosphorus, and potassium.
Nutrients Explained
Lawn fertilizers are a mix of nitrogen, phosphorus, and potassium. You’ll see an NPK ratio on the packaging. It’s a weight ratio of the three units, and then the rest of the fertilizer mix is filler that helps make it easier to deliver and spread the fertilizer over the lawn.
- Nitrogen (N): Promotes leaf growth and green color.
- Phosphorus (P): Helps support root development.
- Potassium (K): Provides support for metabolic processes and stress resistance.
Related: These Are the Lawn Fertilizers Pros Swear By for Thicker, Greener Grass
How Fertilizer Benefits Your Lawn
Fertilizers are designed by chemists to optimize the health of grass. While there are many different types available, the general goal for fertilizers is for a greener lawn that’s thicker and has better resistance to stress, weeds, drought, and disease.
How to Choose the Right Fertilizer
Some fertilizers are fast-acting and others are slow release. The best fertilizer for your lawn depends on your grass and your goals.
Granular vs Liquid Fertilizers
If you are weighing granular vs liquid fertilizers, there’s a lot to consider. Generally, granular fertilizers are much less expensive than liquid options, but they require a hopper to apply them. Liquid fertilizers usually come ready to attach to a hose for application.
And while there are easy online subscription services for liquid fertilizers, many experts recommend granular for DIYers. The reason is that it’s harder to control a liquid spray application methodically and not overdo it or underdo it than it is to apply granules with a hopper. Plus, if sustainability is a priority for you, there are more organic options for granular than for liquid.
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Slow‑Release vs Quick‑Release
Granular fertilizers also are usually slow-release, which means that they have a longer rate of absorption which can be ideal for making sure your lawn has access to nutrients over time and reducing the number of times the fertilizer needs to be reapplied. However, if you are looking for a quick-fix for your lawn and green results within a few days, a liquid quick-release may be a better option.
Fertilizer for Grass Type
Grass type is another major consideration when selecting a fertilizer plan. Many grasses in the northern states are cool-season grasses like fescue, bluegrass, and ryegrass. They can be mowed to about two inches or less and thrive just fine. These grasses benefit from a fertilizing schedule that starts in early spring and ends in late fall when soil temperatures are around 50 degrees.
Warm-season grasses like zoysia, Bermuda, and St. Augustine are often found in southern states. They tend to require fertilizer every six to eight weeks from spring throughout the summer until the soil temperatures dip below 70 degrees.
Related: Is Spring a Good Time to Aerate Your Lawn? Experts Weigh In
Tools You’ll Need to Fertilize Your Lawn
In order to fertilize your lawn, you’ll need a few supplies.
- Spreader (broadcast or drop)
- Measuring scoop
- Gloves, eye protection, mask, pants, closed-toe shoes
- Hose or sprinkler
- Soil test kit
“The key tool is a spreader, which helps apply fertilizer evenly. The size you need depends on your yard,” says Brown. “It’s also a good idea to use basic safety gear like gloves and eyewear during application. For homeowners who want to be more precise, soil testing kits can help identify nutrient deficiencies and guide more targeted treatment.”
Isaac Mertz, Ph.D., regional technical manager of the Carolina region of TruGreen, adds: “Opt for a rotary (broadcast) spreader rather than a drop spreader when distributing fertilizer.” A broadcast spreader is easier for DIYers to use and helps them keep track of the amount and location of the fertilizer being distributed.
Related: Is Spring Really the Best Time to Dethatch Your Lawn? It Depends on Your Grass Type
How to Fertilize Your Lawn
Any DIYer can learn how to apply lawn fertilizer. Here are lawn fertilization steps using granular fertilizer with a broadcast spreader.
1. Prepare the Lawn
Before you begin, make sure to check the weather forecast to make sure no heavy rainstorms are expected. Then prepare the lawn for the fertilizer. Clear away any leaves, sticks, and pet waste, and then mow the lawn.
2. Test Your Soil
Test your soil for both temperature and nutrient makeup. When applying fertilizer, the temperature of the soil should be greater than 55 degrees Fahrenheit. At this temperature, the grass is no longer dormant and it should be actively growing. If you don’t own a soil thermometer, you can ask a local university for soil data.
Also, find out what nutrients are lacking in your soil through a soil test. This will show you what NPK ratio is appropriate for your lawn. A soil test can also tell you the soil pH, which is helpful when choosing the right fertilizer.
3. Set Up Your Spreader
“Configure your spreader according to the manufacturer's guidelines on the product bag,” says Mertz. Shut the spreader’s hopper and put a tarp under the spreader before you fill it so you can easily gather any spills and then “fill your spreader on a paved surface to prevent accidental damage to grass.”
In order to prevent over-fertilizer, set the spreader to half-open.
4. Apply Fertilizer
Here are two methods you can use to apply fertilizer:
Weave pattern
Begin by walking with the spreader around the perimeter of the property at a steady pace. Then methodically walk back and forth in a striped pattern, using the wheel marks as the guideline for each row. After applying the fertilizer in one direction, then go in the perpendicular direction. Keeping the spreader half open ensures you won’t over-apply the fertilizer with this method.
Overlap pattern
Walk the spreader in rows, starting on one edge of the lawn. “During application, maintain an even walking speed and ensure you create a 50 percent overlap with each previous pass—your granules should cover the footsteps from your previous direction,” says Mertz.
5. Water After Application
Watering right after applying fertilizer can help it to work more effectively by directing nutrients down into the soil and the roots of the grass. “Lawns need a food source along with proper watering,” says Lou Manfredini, Ace Hardware’s home expert. “And the right amount of food and water creates a thick green lawn that is disease-resistant and promotes deep root growth.”
Just keep in mind that throughout the growing season, more watering can require more fertilizing. (It’s similar to human bodies and our need for electrolytes.)
How Much Fertilizer to Use (and Why It Matters)
“Too much fertilizer can burn the grass, make the blades limp, or harm water uptake,” says George P Carrette, owner and operator of EcoQuiet Lawn Care LLC. “Remember in Idiocracy when they kept putting Brawndo on plants and the crops died? Well guess what? Fertilizers can create the same problem.”
It’s essential to read the labels before you choose a fertilizer and select one that’s appropriate for your grass type and climate. And then make sure to calculate how much you’ll need for your lawn. An online calculator can help you decide how much to purchase based on the type you need and the square footage of your lawn. Some online fertilizer calculators like the one from the University of Georgia include details about the NPK ratio, too. However, generally, the ratio is one pound of fertilizer for 1,000 square feet.
What to Do If Fertilizer Isn’t Working
The good news is that your lawn can’t hide when it’s not doing well. “Your lawn will usually give you visual cues—thinning grass, lighter green colors, and brown or patch areas—that it’s lacking nutrients or struggling to stay healthy,” says Brown.
“If you’re not seeing results [from a fertilizer], the most likely issue is that your lawn isn’t getting the nutrients it actually needs. The best next step is to test your soil. That will tell you exactly what’s missing so you can choose the right product instead of guessing,” Brown says.
While you can buy a kit online and DIY your soil testing, you might want to “find a local soil lab and get a soil test to find the right mix for your lawn,” says Carrette. “You might be over-fertilizing some nutrients or under-fertilizing others.”
Signs that fertilizer isn’t working include the following:
- The lawn is still pale or thin.
- There are patchy green areas.
- You notice signs of fertilizer burn.
Related: If Your Lawn Looks Dead, Grubs Could Be the Culprit. Here’s How to Wipe Them Out Fast
Lawn Fertilizer FAQ
How often should I fertilize my lawn?
Lawns usually thrive when fertilizer is applied every six to eight weeks during active growth, which is from early spring through the fall.
Can I fertilize in the heat of summer?
Yes, you can safely fertilize grass during the summer months. Choose either a lighter application than spring fertilization or you may want to use soil food to help balance the pH. Proper watering is also essential during the summer.
Do I need to soil test?
Yes, soil testing is key to knowing what your lawn is lacking and what type of fertilizer is best suited for your lawn. Soil test results help ensure that you’re applying the right nutrients.
Can I apply fertilizer before rain?
It depends on the amount of rain. It can be helpful if there was a recent light rain or morning dew as it helps the fertilizer to stick to the grass. However, heavy rain may make it tough for the fertilizer to stay in place and too much water can wash nutrients away.