What’s The Best Lawn Fertilizer Ratio?

This post may contains affiliate links. If you click and buy we may make a commission, at no additional charge to you. Please see our disclosure policy for more details.

The best lawn fertilizer ratio usually consists of nitrogen that is 3 to 4 times the phosphorus content. The potassium should be half or a little less than half of the nitrogen content. Ratio wise, 3-1-2 or 4-1-2 is considered ideal for most types of gardening activities. 

Lawn Maintenance: What’s The Best Lawn Fertilizer Ratio?

best lawn fertilizer ratio

Although this ratio can fluctuate based on the weather at the time of application. Early spring, late summer, mid-winter, rainy, etc. all will restrict fertilizers to portray their full effects to some extent. Even the purpose of fertilization is a factor that influences the desired N-P-K ratio. 

In case you do not know what N-P-K is, it stands for Nitrogen-Phosphorus-Potassium. Potassium’s chemical denotation is ‘K’.

#1. Examining Fertilizer Labels

Reading through the method of application is one part. The real details lie in the N-P-K ratio. Depending on your soil type and type of grass seed, the right N-P-K ratio can vary. Another vital piece of information is the nitrogen-type that the fertilizer contains.

Best lawn fertilizer ratio

Following are the 2 nitrogen types:

1. Slow-release Nitrogen

Also known as water-insoluble nitrogen, will not let the nitrogen particles break down soon enough. On the contrary, the nitrogen particles gradually breakdown over a prolonged period of time. Due to its slow-release feature, lesser instances of the application are required.

If you are growing warm-season grass then applying slow-release N-P-K fertilizer a month before the winter season would be wise. This replenishes the soil with nutrients that the cold climatic conditions would otherwise deprive them of. 

best fertilizer lawn ratio

2. Quick-release Nitrogen

Also known as water-soluble nitrogen, allows the nitrogen particles to break down much faster. This helps in attaining instant results when you are trying to increase the greenery of your lawn. 

The major drawback of this type of nitrogen is that it can easily over-fertilize the grass. This would burn out the outer layering and kill the growth cycle completely. Make sure you are applying these fertilizers in moderate amounts. There should not be any excess spilling and it must be evenly distributed. 

best lawn fertilizer ratio

If you fertilize your lawn regularly, then consider mixing the fertilizer in these high-quality backpack sprayers.

Are you an old-school gardener?

If yes, then this watering can by Bosmere Haws be an impressive addition to your watering equipment.

#2. Macro-Nutrient Requirements

As nitrogen is the prime component of the N-P-K ratio, the best lawn fertilizer ratio must impart the ideal rate of nitrogen for grass growth. By thumb rule, one pound of nitrogen per 1000 sq. ft. is considered healthy. Thus if your fertilizer ratio is 24-8-16, 6 pounds of fertilizer for each 1000 sq. ft. a chunk of your lawn is enough.

lawn fertilizer ratio

Speaking of grass, it gets ample of macro-nutrients from its surrounding environment. But supplementary nutrients are what count in imparting long-term benefits. Using fertilizers permits a chain of actions that allows the plants to absorb the provided nutrients. 

For example, Potassium permits the soil and grassroots to increase the intake of nitrogen (which sharpens the leaf growth and color). Whereas phosphorus establishes quicker root development.

Best Lawn Fertilizer Ratio Depends on Nutrient Requirements

It is easy to think that if the fertilizer is equipped with plenty of nutrients, your grass growth cycles will be enhanced. The fact is that nutrient intake depends solely on the nutrient requirements of your plant. Simply adding fertilizers does not mean your plants will soak them in and begin to flourish. 

best lawn fertilizer ratio

It is a two-way process. The plant will only take what is required. When excessive fertilizers are used, you are forcing the plant to consume more than its nutrient demand. This could lead to fixation or leaching. 

Keep in mind, the best lawn fertilizer ratio can also be determined as N-0-0. This is because the extra nutrients aren’t necessarily benefiting the turf, provided you are following the basic maintenance routine. Most often, grass is nitrogen deficient. Significant nitrogen-focused fertilization will be a stepping stone to satisfying nutrient demands.

lawn fertilizer ratio

Best Lawn Fertilizer Ratio Based on Grass and Soil Type

As mentioned earlier, the kind of soil and grass seeds used have an important role to play in determining the fertilizer concentration. This table reveals the ideal ratio for some common grass and soil combinations used by gardeners all over the world. 

Grass TypeSoil TypeRemoved ClippingsExisting Clippings
Kentucky Bluegrass, Perennial Rye-grass, and other cool-season grassNative Soil4-1-38-1-4
Sand-Based Soil4-1-48-1-8
Creeping Bent-grass TurfNative Soil4-1-36-1-4
Sand-Based Soil4-1-46-1-6
  • Removed clippings denote that there is no lawn waste present above the area of fertilizer application. Also known as thatch, the absence of these clippings means fertilizers have an easy route to the soil.
  • Existing clippings denote that there is a thatch present. This could be in the form of broken stems, dead grass, leaves, or living shoots in the middle of the soil and exposed grass. These elements act as a barrier for the fertilizer to be soaked by the soil and grass respectively. 
best ever lawn fertilizer ratio
  • As you can see in the table, when clippings aren’t cleared, the ratio of nitrogen and potassium increases considerably. This is to ensure that the extra fertilizer reaches the soil and doesn’t get soaked by the thatch itself.
  • As you can see in the table, phosphorus content is supposed to be low in fertilizer ratios for all kinds of soil and grass types.
  • The type of soil you use will determine whether or not you need a little bit more of both, nitrogen and potassium. Although the nitrogen content is almost the same for native and sandy soil, it is the potassium content that fluctuates. Sandy soil generally has a lower potassium content, thus the fertilizer you use must account for this.
best lawn fertilizer ratio

Lawn Fertilizer Ratios for Different Lawn Types

This table should give you an idea of what elements among N-P-K must be prioritized when taking up different lawn grass management projects.

Lawn TypePurpose of FertilizationNPK
New LawnTo improve the development of rootsLowHighHigh
New SodTo strengthen newly developed rootsLowHighHigh
Established LawnTo improve leaf growth and uniformityHighLowLow
Damaged LawnTo replenish damaged grass and patchesHighLowHigh
best lawn fertilizer ratio ideas

Tips To Making the Most of an Ideal Lawn Fertilizer Ratio

Getting your hands on the perfect ratio of an N-P-K fertilizer is only half the battle won. How you apply these fertilizers will indicate the effectiveness that it brings to your garden. 

Here are a few tips the make the most of a product with the best lawn fertilizer ratio:

top lawn fertilizer ratio
  • Some fertilizers are solely for the initial stages of lawn grass growth. Be it seeds, sod, or plugs. Using these fertilizers once your garden is already showing significant grass growth would not help as the essential nutrients needed for growth have already been stored.
  • Weed fertilizers must be used based on their precise method of application. Some fertilizers are made for equipping the soil to fight weeds before weed formation. Whereas some are to be applied once weed growth is evident. Using the fertilizer in the wrong manner will have no effects on weed development in the long run.
  • Perfect lawn fertilizer ratios are only helpful when you apply them during the peak period of active growth. This is because this period calls for extra nutrients. Cool-season grass such as Tall Fescue should be applied with fertilizers during early fall or early spring. 
lawn fertilizer ratio

Whereas warm-season grass such as Zoysia must be fed with fertilizers for weeks at a time during peak summer growth.

  • Every lawn will benefit from one final fertilization session just before early fall or late summer. Make sure you perform this application around 6 to 8 weeks before winter arrives. There is no better way to equip your grass for the cooler months. 
  • There is a reason fertilizer manufacturers put up a label on each fertilizer bag. Following their instructions and verifying that the ratio is suitable for your grass type can reward you with an attractive lawn for several years.
lawn fertilizer ratio


There are multiple layers of benefits when using lawn fertilizers. Breaking them down will reveal the perks of using the fertilizer with the ideal N-P-K ratio.

Also, check some of the related articles.

Leave a Comment