When to Apply Lawn Fertilizer

There can be an abundance of conflicting information to sift through in regards to lawn care and maintenance, especially in regards to fertilizing your lawn.  Some lawn care enthusiasts swear by one lawn program while others speak of its failures.  When should you fertilize your lawn for the best results, and how frequently should you fertilize?

To make a long story short, the best time to apply lawn fertilizer is in the early Spring and early Fall at a minimum. The early Spring application primes your lawn for the growing season and the early Fall application gets the grass filled in and ready for winter dormancy.

when to apply lawn fertilizer

If you do not fertilize your lawn at the right times throughout the year, you may miss your window of opportunity to make your lawn healthier.  Worse, applying too much fertilizer at the wrong time can kill your grass.

In reality, the depth of your lawn care program is up to you.  Depending on how much time and money you are willing to devote to the process, you can fertilize your lawn anywhere from once a year to every six weeks during the growing season.

When To Fertilize Cool Season Grasses (Northern Lawns)

The most basic fertilizer option that most experts will recommend for homeowners is to fertilize cool season grasses in early fall and warm season grasses in late spring.  Cool season grasses need the boost of nutrients from fertilizer in the early fall months to prepare them for their peak growth in the late fall and wintertime dormancy.

When To Fertilize Warm Season Grass (Southern Lawns)

For warm season grasses, they experience the most growth during the summer months and therefore typically need to prepare with a nitrogen-rich fertilizer in late spring.  If you have never fertilized your lawn before or are a general newcomer to lawn care, it’s best to start with an annual fertilization program so that you are able to experiment with the right spreader, application and overall process.

How Often Should I Fertilize My Lawn?

Some experts say that you do not need to fertilize your lawn more than once or twice a year.  If you think your grass needs a second application, fertilize cool season grasses again in late spring or early summer.  Apply a second spread of fertilizer for warm season grasses if necessary around August.  The general belief among some experts of lawn care maintenance is that a truly healthy lawn does not need even a second application of fertilizer in a given year.

For those who mulch their grass clippings, mulching can account for the same nutritional support as one application of fertilizer in a growing season.  For that reason, if you favor mulching your grass clippings or want a traditional approach, you should fertilize your lawn once or twice a year.

Other lawn care enthusiasts may be looking to take their lawn to the next level.  You may be interested in a lawn care program that involves fertilizing every six to eight weeks during the growing period of a given year, though this plan means more frequent mowing.

Many experts recommend a plan to fertilize four times from April to October: once during the early spring, late spring, early summer, and late summer to early fall.  The ideal temperature to begin fertilizing your lawn in the springtime is 55 degrees Fahrenheit, which the soil typically reaches in April for the Northern U.S.

However, to be as precise as possible you can use a soil thermometer to verify when your soil reaches that temperature.  If you plan to mow your lawn frequently and feel comfortable with how to apply fertilizer, you may be interested in this more detailed lawn care program to achieve an even more impressive lawn.

Our Recommendation

We recommend fertilizing every 6 weeks starting in the early spring as soil temperatures reach 55 degrees Fahrenheit with both regular fertilizer as well as organic fertilizer for best results. Use ordinary lawn fertilizer such as “Lawn Food” for each application except for during mid-summer where you’ll want to apply organic fertilizer such as Milorganite due to the high temperatures and the heat. During the heat of summer, your lawn becomes stressed with the heat and it’s definitely not the right time to push growth with normal fertilizer.

Organic fertilizers help because most are “slow release” meaning that they release nutrients into the soil slowly as to not hurt your lawn. Unlike chemical fertilizers, organic fertilizers can be applied in large quantities without the risk of burning your lawn.

Time Your Lawn Fertilization Right For Best Results

Regardless of the frequency with which you choose to fertilize, there are a few tips that always remain true about fertilizing.

If possible, plan to fertilize your lawn the day after a substantial rainfall.  However, do not fertilize right before a heavy rainstorm, because the rain will most likely wash away the newly laid fertilizer before it has been absorbed.  A slow-release fertilizer is the best choice, because it provides long-term nutrition and allows you to fertilize less frequently.

Water Your Lawn

It’s vitally important to water your lawn for best results, especially after fertilizing. You can either time your fertilizing after a heavy rainfall or fertilize before a light rain if you want to water naturally (also without the expense of watering). You can also set out the sprinklers after you’re done fertilizing but don’t over-do it. I would recommend watering for about 15 minutes after fertilizing with a standard lawn sprinkler. Water is basically the number one driving force for a green lawn.

No Matter What, Fertilize Your Lawn

As you can see, there are a number of different options for applying fertilizer throughout the year.  The baseline program for lawn fertilization is to dispense fertilizer to cool season grasses in the early fall and to warm season grasses in the late spring; beyond that, you can choose based on your lawn health and your level of commitment whether you need a more rigorous program.

Keep in mind, as well, that some lawn care enthusiasts rely on mulching alone to fertilize their lawn.  Others do not agree with using chemical fertilizer products and find other ways to nurture their lawn with essential materials.

Whether you are a beginning lawn care enthusiast or a seasoned pro, there is no one right way to fertilize your lawn.  Choose the plan that is right for you based on your time commitment, cost considerations and overall lawn health.