What Do The Numbers Mean On Fertilizer Bags?

You know it’s time to fertilize your lawn, so you head to the store. As you walk through the fertilizer aisle, you notice three numbers on the front of each product.

The first reads “23-3-8.” The second one is marked with “30-0-4.” Bags three and four also sport a series of three digits. You aren’t sure what these numbers mean or which seasonal blend your lawn needs to reach its maximum beauty.

Understanding these numbers, buying the right amount of fertilizer, and applying it at the proper rate and times of the year will empower you to achieve the beautiful lawn you desire.

Here’s what you need to know.


The first number listed represents the percentage of Nitrogen in the bag.

Nitrogen helps your grass to appear green, lush and thick. Nitrogen aids in the creation of chlorophyll, which is responsible for producing the green pigment in grass and is the compound by which plants use sunlight to produce sugars from carbon dioxide and water.

Nitrogen or “N” stimulates new root growth. Many early spring fertilizers will have a higher Nitrogen level to give the lawn a kick and get it growing early. It can help turf recover from environmental stresses and injury. An application of nitrogen in the spring, and then timely spreading throughout the growing season will help fortify turf to better withstand environmental stresses such as heat and insects.


The second number represents the percentage of Phosphorus.

Phosphorus is critical in developing and strengthening a healthy root system of turfgrass. If only Nitrogen is applied to the lawn, the grass will be nice and green, but as watering or a drought hits the grass will be greatly impacted. Having strong roots in your grass will keep your lawn healthy through the changing weather and stresses of the seasons.

Phosphorus or “P” is a primary plant nutrient that is involved in the metabolic processes responsible for transferring energy throughout the plant. It’s crucial to introduce phosphorus when first establishing turf grass and continue application as the grass grows. An abundance of phosphorus allows plants to grow more efficiently.


The final number is the percentage of Potassium.

Potassium is important to overall plant health. Potassium or “K” supports the internal process of the plant cells that affects photosynthesis, water absorption, respiration and protein production. A deficiency of potassium weakens a plant and increases its vulnerability to drought, temperature fluctuation injury and disease.

Adding soluble potash (K2O) to the soil helps grass withstand stress, drought, and disease. Specifically, potassium helps maintain pressure in the cells of the plant, resulting in a positive influence on drought tolerance, cold hardiness, and disease resistance.


The amounts of the macro nutrients (N, P, K) in each bag of fertilizer vary from season to season. They change based on the nutrient requirements of turfgrass for the upcoming weather and temperatures expected for the next 6-12 weeks.

The IFA 4-Step Plus annual lawn care program is locally formulated and specifically designed to help produce the best results in the Intermountain West. With two of our four applications, we also use Omnicote Technology that allows micronutrients such as Zinc, Iron, and Manganese to coat every prill of fertilizer and thus getting an even nutrient distribution on the lawn. These elements may not require the quantity of the three major elements, but they are just as important. When applied in conjunction with each other, IFA 4-Step Plus maintains the rich, deep green lawn you desire each season, while also building stronger, healthier turf for future years.

As always, let the good folks at IFA Country Store help answer questions when you’re walking through the fertilizer aisle on your next visit. The success and beauty of your lawn is important to us.

Information for this article was provided by Brad Schumann, Branch Manager, Logan IFA Country Store; Bret Yardley, Branch Manager, Richfield IFA Country Store; and Ken Holt, Lawn & Garden Category Manager, IFA Country Store.