Fertilizing Your Lawn: Grass Seed or Fertilizer First?

By: Ken Wilson

The two essential components needed for a deep green, healthy, and dense lawn are fertilizer and grass seeds. Both components need proper planning and execution to enjoy a lush lawn. The confusion about whether you must first sow and then feed or vice versa is a question many ask and one I will answer in this article.

Sowing grass seeds before or after fertilizing is both correct methods and depends on factors like soil condition and nutrients needed for growth. Sowing grass seed before and after fertilizing has pros and cons affecting the root strength and seed growth.

Although sowing grass seed before or after fertilizing is an accepted method, it is essential that you understand, consider, and weigh each option to make an informed decision. This article discusses both methods to help you get the best results and enjoy a beautiful green lawn.

What Do You Put Down First: Grass Seed or Fertilizer?

Whether you start a lawn from scratch or repair some bare patches, grass seed, and dressing are necessary. One of the most frequently asked questions regarding planting seeds is which comes first, the fertilizer or the seeds. The answer depends on various factors. Both methods have advantages and disadvantages that vary depending on your specific circumstances.

You must consider how it will influence your lawn’s growth before you decide to nourish before or after seeding. Both methods provide good reasons, and below, I explain the benefits of each and for combining them.

Using Fertilizer Before Seeding

Beautiful, lush lawns require nutrient-filled soil to grow; not every piece of land has good soil quality ready for grass seeds. Here are the reasons and benefits to feed your soil before planting the seeds:

  • Grass needs phosphorus, nitrogen, and potassium for root growth due to its shallow root system. Without the proper nutrients in the soil, your seedlings will struggle to form roots and simultaneously slow growth, and feeding the soil first gives it a good start.
  • Fertilizing before sowing the grass seeds improves the germinating process. The soil will have better drainage while keeping moist and filled with the necessary nutrients to produce strong roots.
  • Seeds’ biggest enemy is weeds; providing the seeds with the best growing environment will cause them to outgrow and suppress the weeds.
  • Feeding before sowing allows you to till the soil and ensure it has good nutrient coverage, drainage, and the ideal root growth density.

Fertilizing before seeding has numerous benefits, but there are some challenges you must consider:

  • It’s difficult to fertilize before sowing when there’s no lawn to reveal areas needing nutrients.
  • Fertilizing before seeding sometimes causes over-fertilization, which leads to burned grass seeds.
  • Fertilizing the soil is time-sensitive, and if left too long before sowing, the grass seed allows the weed to establish itself.

Using Grass Seed Before Fertilizer

Sowing grass seed before fertilizing has some advantages, especially if the current soil shows signs of nutritional value. Sowing before fertilization is also popular when covering some bare patches.

Here are the reasons and benefits of sowing the seeds before fertilizing:

  • Grass requires a strong root system and sowing them before fertilizing provides the ideal environment for them to develop deep and strong roots and make them resilient in the long term.
  • Seedlings require less nutrients than fully grown lawns, and sowing first prevents excessive nutrient absorption.
  • Sowing the seed first reduces the risk of seed burn, which happens when high nitrogen levels in the fertilizer damage or kill delicate seedlings.
  • Fertilizing after sowing will show you where your soil lacks nutrients so that you can target bare and light spots.

Sowing grass seeds first has its advantages, but there are a few challenges to consider:

  • Grass seeds have their initial nutrients but still require some soil nourishment. Poor soil will restrict or prevent growth and damage the root establishment.
  • Sowing before fertilizing may cause bare spots that must be addressed afterward, making the process a little longer.

Combined Application of Grass Seed and Fertilizer

You must consider your specific situation when sowing grass seeds. Some instances require fertilizing before and others after, but another option exists. Sometimes, your situation requires a combined process. Combining the two methods is somewhat tricky, but it has benefits like:

  • Making it a single step saves time and reduces costs, which makes it more efficient.
  • Applying both components together gives seedlings immediate access to the necessary nutrients for optimal growth and root development.
  • Combining both methods provides consistent and equal growth, reducing the chance of bare patches.

Combining the two methods is great, but it has some downside factors to consider:

  • Applying a combined method evenly to your soil is much harder.
  • Combining the grass seed and fertilizer requires precision, especially with the nutrient value in the feeding.

What is the Best Fertilizer for New Grass Seed?

Fertilizer is the fuel seeds need to achieve their full potential, and various factors must be considered. Choosing the correct feeding depends on the application, soil quality, and other factors, and here are three great fertilizer starters to consider.

1. Scotts Turf Builder Starter Fertilizer For New Grass: Scotts Turf Builder Starter Fertilizer provides everything you need to get a new lawn going, patch bare spots, and reseed existing lawns. With a 24-25-4 ratio, it is ideal for all types of grass, especially for new seeds. The packaged nutrients provide a perfect balance, promoting strong roots for healthy growth and lush green grass.

2. GreenView Starter Fertilizer: Grass seeds need a good initial nitrogen boost plus a gradual release to optimize growth and form strong roots. GreenView Starter Fertilizer is ideal for seedlings due to its eight weeks of continuous nutrient release, which gives the seeds time to establish themself. The amazing quality of this product makes it usable as a before or after-sowing nourishment.

3. Andersons Premium New Lawn Starter Fertilizer: Everyone wants that deep green lawn envied by their neighbors, and Andersons’ Premium New Lawn Starter Fertilizer is what you need to get you there. Its 20-27-5 ratio balances phosphorus, nitrogen, potassium, and other micronutrients, including 1% iron. Seed benefits from this product due to its balanced formula that encourages strong roots and dense growth.

Final Thoughts

Fertilizing before or after sowing your grass seeds are two methods used to patch or start a new lawn, and both work. Each method provides a different outcome and relies on soil quality and nutrients to supply the seeds with everything they need to establish strong roots and healthy growth.

About the author 

Ken Wilson

Long time career in the home services industry from remodeling to patio construction. Currently residing to in SWFL and active contributor to multiple home & garden publications.