Should I Fertilize Or Seed First? + [More Tips]

Should I Fertilize Or Seed First

A plush, thick lawn is a desirable asset that can turn your property from ordinary to stunning. However, achieving it requires knowledge of the best lawn care practices. The timing of fertilization and deciding should you fertilize or seed first are some of the factors that determine whether you’ll have the lushest lawn.

So, should I fertilize or seed first, you ask!

Fertilize first before seeding to help improve the soil’s health – thereby, promoting optimal growth of your seed. Apply fertilizer and seeds to the existing grass during spring to keep your turf looking lush and green. Use starter fertilizer before seeding to promote healthy, strong roots. 

Read on to learn how to fertilize and seed during spring and the benefits this offers to your lawn.

Also Check: Can You Overseed And Fertilize At The Same Time?

Should I Fertilize Or Seed First?

If you’re planning to seed a lawn, you shouldn’t apply the seed and fertilizer together. The reason is that it can cause an irregular distribution of the materials ensuing in patchy areas. Excess fertilizer may burn the seedlings, though. Therefore, to be extra careful, it’s advisable to apply fertilizer before planting your seeds. 

Below are the steps to follow when applying starter fertilizer and seeding:

  • Use a 5-10-5 potassium, phosphorous, nitrogen starter fertilizer per every 25sq feet of lawn. Measure the total amount of fertilizer required to cover the whole planting area. 

Place a drop spreader over a firm surface close by and calibrate it to half the rate. You’ll spread the fertilizer in 2 equal portions and thus pour half of the fertilizer into the spreader. 

  • Next, start applying the fertilizer from one corner of your planting site, pushing the spreader back and forth horizontally. Work your way crosswise, overlapping the spreader’s wheels on the outer track of the previous row to warrant even the coverage.  
  • Empty the remaining half of the fertilizer into the spreader and start applying from the same corner as done earlier. This time around, push the spreader vertically across your planting area. 
  • Using a rake, mix the fertilizer into about 2-4 inches of the soil. Working in uniform rows, pull the rake in even long strokes to ensure that the applied fertilizer remains evenly spread. Ensure that you smoothen the soil’s surface as much as possible. 
  • A pre-calculated seeding rate is in pounds per 1,000sq feet. To get the correct quantity of seed you require, divide the number of pounds by 1,000. Then, multiply the figure you get by the square feet in your planting site. 
  • Divide the total amount of seed needed into 2 portions. Pour half of the portion into the drop spreader.
  • Push the drop spreader back and forth vertically over the site. It would help if you overlapped the wheels to ensure you don’t miss any spots.  
  • Next, pour the second half of the portion into the spread and push it horizontally. 
  • Using a weighted roller, push it back and forth horizontally to drive the seed into the soil. 
  • Spread a quarter-inch layer of topsoil over the lawn. To moisten the area, apply a quarter-inch of water lightly. Be careful not to wash away the seeds.   

Why Should I Fertilize Before Seeding?

To achieve a blooming lawn, proper feeding of your grass seeds is vital. Even so, ensure that you choose the best grass seed suitable to your landscape depending on factors such as climate and the purpose of the lawn. 

Fertilization is the most crucial factor to help improve the health of your lawn. Why? Fertilizers add essential nutrients to the soil that supplement the existing ones. 

Some soils are deficient in nutrients critical for a healthy seed growth cycle. Erosion can wash away the soil’s nutrients. Weak soil lacks adequate organic matter to support the proper germination of your grass. 

Furthermore, poor soil attracts insects and weeds and is more vulnerable to diseases such as yard fungus. Without a boost from fertilizer, therefore, you’ll most likely end up with a lackluster lawn with dry patches of grass. 

Also, be careful not to over-fertilize your lawn. Excessive fertilizer can quickly reach into the soil at a higher rate than the roots’ ability to absorb it. 

Over time, the lawn can transform into a cloggy yard with wet grass. These conditions can also encourage weak overgrown turf that contributes to buildup and may force you to mow your lawn too frequently. 

Moreover, too much fertilizer can additionally kill the vibrance of your lawn because of dead-looking grass. 

Which Type Of Fertilizer Should You Use?

Lawns are living creatures that go through various stages of growth. They also need diverse forms of nutrition to support their development throughout the different stages. 

Emerging grass stalks in a new lawn need sufficient nutrients to jump-start their growth. The starter fertilizers have a higher phosphorus percentage which helps promote strong, healthy roots.

When a lawn is in its infancy stages, a starter fertilizer is preferable to a regular fertilizer. Freshly germinated seedlings require high amounts of phosphorus. Phosphorus is a critical ingredient during germination as it stimulates root growth for new seedlings. They also need to release nitrogen very quickly. 

After maturity, lawns can thrive with regular fertilizer, which contains lower phosphorus levels. The use of phosphorus is prohibited in some areas unless you are cultivating a new property. Ensure that you follow legal guidelines when choosing a fertilizer for your lawn. 

When choosing a fertilizer, it’s essential to consider the NPK Ratio. The ratio informs buyers of the fertilizer’s nitrogen, phosphorus, and potassium ratio content. Each of these nutrients plays a different role in supporting the growth of your grass seeds. 

Nitrogen is vital for the growth of leaves and helps your grass look greener. Phosphorus is responsible for the development of roots and stimulating fruit production. Potassium boosts the plants’ immunity and reinforces their ability to withstand extreme environmental conditions. 

A bag of fertilizer labeled “10-10-10” therefore means that it contains 10 pounds of each variety of nutrients and the remaining weight as filler. 

During application, apply regular fertilizers four to six inches away from the roots of the plants. Starter fertilizers are very strong and can burn parts of the seedlings, such as tender leaves, roots, and stems. Before inserting seeds, ensure you dilute the cup of fertilizer for milder effects. 

How To Seed And Fertilize Your Lawn In The Spring? 

The best technique to thicken your lawn is to apply the appropriate fertilizer and seeds to the existing grass in spring. A new application of grass seed during the spring allows it to develop well before it becomes too hot in summer. 

The fertilizer helps the newly sown seed and the existing grass develop healthily. Once the freshly planted seed becomes established, the lawn becomes thick, welcoming, and green.  

It would be best to overseed during the spring when the already existing turfgrass is dormant. Below is the guideline on how to seed and fertilize your lawn in the spring:

  • Mow the lawn so that it’s cropped close to the soil. Using a metal rake, remove any existing thatch. 
  • Apply new grass seed uniformly and evenly to the existing turf using a spreader.  
  • Apply the starter fertilizer as per the package specifications.
  • Spread a quarter-inch layer of peat moss over the fertilized and seeded turf to help protect the seeds and help them sprout. 
  • You should keep the grass consistently moist to help the seeds develop promptly. Continue watering the turf until the new grass is long enough to mow. 
  • Apply more fertilizer to the over-seeded garden after 6-8 weeks to progressively deliver the required nutrients to the turf. It helps keep the lawn green and thick.  


Should I Apply Weed-And-Feed Products Before Or After Seeding?

It’s dangerous to combine weed-and-feed products and fertilizer. When you use herbicides on the lawn before sowing, the chemicals in the products can kill young grass seeds and prevent germination. 

When you use the herbicide before seeding, it’s advisable to wait for 6 weeks before seeding. If you plan to apply the products after planting, wait 6-8 weeks when the lawn has been mowed 4 times before use.

Can You Fertilize During Fall?

The fall season is the ideal time to fertilize your lawn, more so if you’re planting cool-season grass. It allows seeds to be firmly rooted before the cold winter season starts. 


A beautiful and well-maintained lawn requires careful preparation. The seeding process must be conducted in a proper way to encourage optimal growth. Fertilizer is an essential addition to your yard to optimize the lushness of your lawn.

However, timing is critical in achieving a balance that gets the most benefits out of the fertilizer. The decision on “should you fertilize or seed first” can be the deal breaker in nurturing your grass.

Also, following a seeding schedule can increase your lawn’s chances of thriving. Squeeze in your fertilization activities between fall and spring to get the best out of the fertilizer. 

Ensure your lawn is well maintained and frequently mowed to help the fertilizer bring out the best a perfect set of greens in your landscape.