When to Fertilize Your Lawn This Spring for Greener Grass All Summer
As winter winds down, you may be getting eager to spend time in your yard, ideally with lush, green grass under your feet. Fertilizing your lawn can help, and spring is one of the best times to do it. If you’re ready to get your lawn in shape for summer BBQs, we’ve got you covered with all the details you need on the best time to fertilize your lawn, the best fertilizer ratio to use, and more.
Why Fertilizing Your Lawn at the Right Time Matters
Your lawn is delicate and requires just the right care to stay healthy. Aaron Strickland, lawn care and gardening expert and owner at Mr. Trim Lawn & Garden Services, explains that grass should be fertilized up to four times a year and the key to fertilizing at the right time is to do it when your grass is “actively growing.”
Warm-season grasses actively grow when temperatures are above 50° degrees Fahrenheit (F), whereas cool-season grasses grow best between 50° F and 65° F.
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Lawn Fertilization Benefits
By following the right lawn fertilizer schedule, using a fertilizer with the ideal nitrogen, phosphorus, and potassium (NPK) ratio, and applying the fertilizer properly, your lawn will get the best results. Lawn fertilization has many benefits.
Promotes strong root growth
Fertilizer provides essential nutrients, such as nitrogen, phosphorus, and potassium that help turf grow thicker.
Prevents weeds and thinning
A well-maintained and fertilized lawn will produce healthier, lusher grass that will naturally crowd out weeds.
Helps lawns survive summer heat and winter stress
Fertilizer helps your grass’s roots grow stronger and deeper, making them more drought- and cold-tolerant. That’s why it is recommended to fertilize your grass up to four times a year, so it is ready for all different types of weather.
When to Fertilize Your Lawn
Strickland says the exact timeline for fertilizing your lawn will be based on your grass type. Remember, for most lawns, fertilization is needed up to four times per year during the growing season.
Fertilization Schedule
Cool-season grasses (Kentucky Bluegrass, Fescue, Ryegrass) should be fertilized as follows:
- Spring: During April to May to help your grass grow and get ready for warm weather.
- Summer: Late summer fertilization, typically done in late August to mid-September, is vital to keep your lawn healthy in the coming cold months.
- Fall: Get the last one in during late October or early in November to encourage root development and prepare your grass for winter.
Warm-season grasses (Bermuda, Zoysia, St. Augustine) are fertilized from late spring/early summer through mid-summer.
- Spring: May through June
- Summer: July through August
- Fall: September
The key is to space these fertilization cycles apart by at least four to six weeks—basically once per growing season (skipping winter).
Related: With These Simple Tweaks, You Can Stop Moss From Killing Your Grass in Shady Areas
How Often Should You Fertilize Your Lawn?
Most lawn experts recommend fertilizing your lawn every four to six weeks during the growing season, for a total of three to four applications per year. Strickland recommends using a time-release fertilizer along with a calibrated spreader for even coverage, watering your grass lightly afterward, avoiding fertilizing during heavy rain, and following your fertilizer’s directions.
Signs Your Lawn Needs Fertilizer
An unhealthy lawn shows different signs that it’s not getting enough nutrients and it's time to apply a fertilizer, including:
- Slow or thin growth
- Yellow or pale grass
- Bare spots appearing
- Grass recovers slowly after mowing
When Not to Fertilize Your Lawn
One of the biggest mistakes people make when fertilizing their lawn is doing it at the wrong time. Here are some times when you shouldn’t be fertilizing your lawn.
During dormancy
When grass is in a state of rest and not growing (dormancy), it cannot take in nutrients, making fertilizing your lawn a waste of time, fertilizer, and money. Most grasses are in a period of dormancy during the colder months of the year.
Before heavy rain
Checking the weather before fertilizing your lawn is one of the most important steps you can take. If heavy rain is in the forecast, skip applying the fertilizer and wait until the rainy period is over. During heavy rain, the fertilizer may be washed away before it is absorbed.
During extreme heat
High temperatures can already put strain on your grass, especially cool-season grasses. Applying fertilizer during a heatwave could end up burning your lawn.
Related: How to Stop Winter Weeds From Taking Over Your Lawn Come Spring
Tips for Fertilizing Your Lawn Correctly
The first thing you need to do is perform a soil test to assess the health of your soil, especially its pH (acidity) and nutrient levels. The ideal pH level for most grass types is 6.5 to 7.0. This range provides the necessary nutrients for your lawn.
Here are some additional tips to fertilize your lawn like a pro:
- Water the lawn a day or two before fertilizing it.
- Choose a fertilizer with an NPK ratio that is suited for your grass type. Most lawns benefit from nitrogen-rich, slow-release fertilizers. Strickland states that at his company, he normally uses a fertilizer with a 25-5-10 ratio, which works really well for his clients.
- Apply fertilizer evenly using a spreader.
- Choose slow-release fertilizer for consistent feeding.