Lawn Starter Fertilizer vs Regular Fertilizer

You have brand new grass seed or sod. What is the best way to help it get a great start?

Do you really need a lawn starter fertilizer?

We’ll find out the difference between lawn starter fertilizer and regular fertilizer! There is a time and a place for both in your yard care regime.

What is lawn starter fertilizer?

Starter fertilizer is a lawn food that is specially formulated to give new grass a great start! All fertilizers contain nitrogen (N), phosphorus (P), and potassium (K). You may purchase a liquid lawn starter fertilizer or granules.

Each bag of fertilizer will indicate a ratio for these lawn nutrients. For example, a bag with a fertilizer ratio of 10-10-10 will have 10% nitrogen, 10% phosphorus, and 10% potassium. The proportions of these nutrients in starter fertilizer are specially formulated to aid new grass to grow healthy and strong.


Nitrogen helps your yard get that gorgeous, deep green color! It is also an essential nutrient for healthy grass growth. Most starter fertilizers have 10-20% nitrogen.


Starter fertilizers usually contain at least 20% of phosphorus. Phosphorus helps with grass growth and development. It is especially important for good root development – exactly what you need for your brand new grass!


Potassium is helpful for disease resistance, cold resistance, and general hardiness of the grass. This is the nutrient that is probably the least needed in the early growth phases of your yard. Starter fertilizer usually only contains 4-6% potassium.

Lawn food vs. starter fertilizer

We already discussed the ratios of nitrogen, phosphorus, and potassium in lawn starter fertilizer. Regular fertilizer for mature grass usually has different ratios. The recommended ratio of NPK for established grass is usually 20-4-12.

You will notice that established grass needs much higher levels of potassium for disease and insect resistance than new grass. It also needs lower levels of phosphorus. Since phosphorus is most important for grass growth and strong roots, established grass needs less of a dose.

How to use lawn starter fertilizer

Whether you are planting grass seed or sod, a lawn starter fertilizer will give it a good start!

How much fertilizer should you use?

This part requires a little math. A standard rule for lawn starter fertilizer is .5 to one pound of Nitrogen per 1,000 square feet of yard. If you apply too much fertilizer, it can burn the grass. As always, read the bag, and follow any manufacturer instructions.

Some homeowners test the soil content before planting. Take a soil sample to your local extension office, then have them check the phosphorus levels. New grass needs phosphorus to establish healthy roots.

Knowing your soil’s phosphorus levels will help you choose a variety of lawn starter fertilizers with the appropriate amount of phosphorus for your yard.

It is best to put down the starter fertilizer before you plant grass seed or lay sod. Follow these steps for a healthy yard full of new grass:

  1. Determine how much starter fertilizer you need to use.
  2. Apply the fertilizer to the soil with a fertilizer spreader if you are using granules, or a sprayer, if you are using a liquid.
  3. Till the soil, so the fertilizer is worked into the soil 4-6 inches deep.
  4. Plant seed or lay sod in the prepared soil.
  5. Water the area thoroughly.
  6. Wait 6-8 weeks before applying fertilizer to the new grass.

If you are overseeding, apply the lawn starter fertilizer before you spread the seeds. You won’t be able to till the fertilizer into the soil, but the new grass should still get some of the benefits of the fertilizer.

Is starter fertilizer necessary for grass seed?

While starter fertilizer may not be strictly necessary for new grass, it will definitely help with growth, root establishment, and that gorgeous, green color!

Brand new grass can be very fragile in its early growth phase. It is nice to give it all the help you can!

Can I use starter fertilizer on regular grass?

Lawn starter fertilizer probably won’t hurt regular grass (unless you use too much!) However, it doesn’t have the right balance of nutrients your mature grass needs. Established grass requires more potassium. A standard weed and feed or other fertilizer will be much better for your grass.

Final Thoughts

Give your new grass the best start possible with a lawn starter fertilizer! The precise blend of nutrients is just what grass seed or sod needs to grow strong and healthy.

Follow up with a regular fertilizer after 6-8 weeks, then enjoy your green, healthy grass!