Person cutting lawn

The Macronutrients You Need for Lawn Care

Everyone wants a green lawn that makes the whole neighborhood wonder what they’re doing differently, but the secret to a quality lawn is simple. There are only three letters you need to know to have a high-quality lawn: NPK. These three letters represent the three main macronutrients for lawn care, Nitrogen (N), Phosphorus (P), and Potassium (K). These are often called the fertilizer elements of lawn care. Below we break down the most important macronutrients for lawn care, including primary and secondary macronutrients.

Close up of green grass

Primary Macronutrients for Lawn Care

These macronutrients for lawn care are the ones you’re most likely to hear people talk about in regards to a beautiful, healthy, high-quality lawn. They’re also the macronutrients for lawn health that you’ll see on almost every fertilizer container, so it’s important to familiarize yourself with them.

  • Nitrogen (N)

Nitrogen is the macronutrient responsible for the growth and coloring of your lawn. This makes nitrogen a vital nutrient for a high-quality lawn. If your lawn is experiencing a nitrogen deficiency, you’ll see slow growth, thin, patchy areas that allow weeds to grow, yellowing or browning patches, and an increased likelihood of disease. If your lawn appears to be fine but you notice fewer grass clippings after you mow your lawn, that could be a sign that your lawn needs more nitrogen. Nitrogen is an essential part of your lawn care routine. It is estimated that mature lawns need around four pounds of nitrogen for every 1,000 square feet per year. However, there should be no more than one pound of nitrogen applied at a time.
  • Phosphorus (P)

Phosphorus helps to stimulate root growth and enhance overall plant health from the first sprout. For this reason, phosphorus is most important when your lawn is first seeded and starting to sprout, but it remains an important component of plant growth as grass continues to root and grow over the season. Phosphorus will turn your lawn from just another patch of grass into a high-quality lawn by keeping your lawn lush and thick from spring through fall. It’s best to test your soil for phosphorus content every three to four years because too much phosphorus can be harmful to your lawn as well. Excessive phosphates in the soil can cause an increase in the growth of weeds, and runoff phosphorus that ends up in water sources can cause the death of fish and other nearby aquatic animals. 

  • Potassium (K)

Potassium is the macronutrient responsible for facilitating some of the most crucial internal processes of the plant cell, including photosynthesis, respiration, water absorption, and protein production. Potassium is also important for strengthening the overall health of the plant to make it less susceptible to drought, heat, cold, and diseases. It does this by strengthening the cell walls of the plant. You might notice that your lawn has a potassium deficiency if your grass has stunted growth and is yellowing in color. Since potassium helps root growth, it’s also important for the absorption of other nutrients. Strong and healthy roots are better able to pull nutrients from the soil, so your lawn will grow faster and create a soft, vibrant lawn. You’ll likely notice if your lawn is low on potassium because the roots will begin to die and your lawn will start to see areas of grass dying completely. Potassium is a key macronutrient for lawn health and one that will go a long way in ensuring you have a quality lawn.

Now that you know what these macronutrients do for lawn care, it is important to understand how to include these macronutrients into your lawn care routine. Any fertilizer you buy should have the letters NPK on the label. Next to each of these letters, you should see a number. For example: N 17, P 5, K 9. This would mean there is 17% nitrogen, 5% phosphorous, and 8% potassium. If you need to figure out how much is in each bag, you would multiply the percentage by the weight of the fertilizer. The other materials in fertilizer are typically secondary nutrients — micronutrients — and inactive ingredients that help to evenly distribute the fertilizer and prevent your lawn from getting chemical burns. In order to ensure you’re applying the correct amount of macronutrients for lawn health, you’ll want to look at the percentages on each package and determine which one is right for your lawn care plan.

Corgi walking around lush green lawn

Secondary Macronutrients for Lawn Care

Secondary macronutrients for lawn health are as necessary as the primary macronutrients, but many are already available from the soil or the air. Your lawn may still need additional support in getting these macronutrients though, so we recommend performing a soil test to determine the proper macronutrients for your lawn.

  • Calcium

Calcium is a secondary macronutrient for lawn health that helps the growth and development of cell walls. Strong and well-developed cell walls help plants resist disease and other external factors that can cause harm or plant death. Calcium also helps in the metabolism of the cell and in the plant’s uptake of nitrate. In addition to helping your lawn be healthier, calcium will also improve the texture of your soil. Calcium is a key macronutrient in ensuring you have a high-quality lawn by summertime.

  • Magnesium

Magnesium is crucial for having a quality lawn because it is responsible for the green coloration of the plants through the formation of chlorophyll and enzyme activators. In order for your lawn to transfer energy, form protein, and go through the process of photosynthesis, it will need access to the proper amount of magnesium. You might notice magnesium deficiency by yellowing of your grass that starts at the tips and spreads throughout the entire blade. Although magnesium deficiency can look similar to nitrogen deficiency, magnesium deficiency has a more mottled coloring. If your grass starts yellowing, pay close attention to what that process looks like because it can help you determine what kind of macronutrient deficiency you may have.

  • Sulfur

Sulfur is a powerhouse macronutrient for lawn health. It is nature’s defense system to weaken disease, grow seeds, and produce amino acids, proteins, enzymes, and vitamins. Not only that, but sulfur helps balance the pH levels of your soil. If your soil is more alkaline than it should be (think sand and silt), your lawn may not be able to absorb all the nutrients it needs. When soil is too acidic or alkaline, it prevents your primary macronutrients — nitrogen, phosphorus, and potassium — from dissolving. This means your lawn can’t absorb these essential nutrients through their roots. If your lawn has a sulfur deficiency, you will likely see yellowing of the blades partnered with stunted growth and spindly blades. Sulfur is crucial to proper lawn care, especially when balancing pH levels so you should pay close attention to signs of sulfur deficiency.

You might be wondering where to get all these macronutrients for lawn health and how to apply them. The good news is, most fertilizers you buy will have some, if not all, of these macronutrients! Organic matter also contains secondary nutrients for your lawn. You can be assured they will all list the percentages of the primary macronutrients right on the packaging. The more difficult part is figuring out which nutrients and at which percentage your lawn needs these macronutrients. To figure that out, it is best to do soil testing.

Soil Testing for Lawn Care

Performing a soil test is a quick and easy process to make sure your soil has the nutrients it needs for your lawn to grow successfully. A soil test will help you figure out what kind of fertilizer you need, what percentages of nitrogen, phosphorus, and potassium will benefit it the most if your soil is too acidic or alkaline, and if you should buy a fertilizer with any specific micronutrients.

So, how do you take the perfect soil sample to ensure a high-quality lawn at the end of all your effort? The soil sample should be taken from specific areas that will all be growing the same plant. This means you want to make sure you’re not taking soil samples from your flower bed and lawn, but only from the specific area, you’re focusing on. You want to make sure you use a clean digging tool as well to ensure no contamination of the sample. Although you can take a soil sample in the middle of the summer, it is best to take the sample before the growing season, so either in late fall or early spring. The sample should be a mixture taken from several sample sites around a large area. A medium-sized lawn should have about 12 sample sites mixed together. Each soil sample should have been taken from a three- to four-inch hole. Once you’ve obtained your various soil samples, you’ll want to mix them all together, give them a day or two to dry out, and then place in a labeled plastic bag and send to a soil lab. The results of your soil testing should provide you with an accurate assessment of the soil’s nutrients, its pH levels, present organic matter, and any possible contaminations.

Most public universities with research facilities will have a soil lab that will analyze your soil for a small fee. You can find a list of some public universities here.

Micronutrients and Lawn Care

While macronutrients for lawn health are incredibly important, micronutrients are important to consider when you’re thinking about lawn care as well. In order to have a high-quality lawn, you’ll want to be educated on both micronutrients and macronutrients for lawn growth. Below we’ll quickly go over some of the main micronutrients you’ll want to consider when testing your lawn and choosing a fertilizer.

  • Boron

Boron regulates the metabolism of carbohydrates and sugars in plants. It also assists new plant growth by helping your lawn absorb nutrients and in the pollination and fertilizer of plants.

  • Copper

Copper is necessary for activating enzymes within the plant and is essential to produce chlorophyll. Copper also helps fortify cell wall strength.

  • Iron

Iron is another micronutrient necessary for chlorophyll production. Chlorophyll also assists in carrying out other cellular functions.

  • Chloride

Chloride is crucial for photosynthesis in plants. It also assists with gas exchange and root development. Chloride can also protect your lawn against diseases.

  • Manganese

Manganese helps with chlorophyll formation and breaks down carbohydrates within the plants. It also activates enzymes during the growth process.

  • Molybdenum

Molybdenum helps plants utilize the macronutrient nitrogen. Without molybdenum, your lawn won’t be able to transform nitrogen into the amino acids it needs.

  • Zinc

Zinc helps regulate the metabolic activity in plants and aids in their consumption of sugars. It is also crucial for healthy root and plant growth and helps with the production of chlorophyll.

Now that you know all the micronutrients and macronutrients for lawn growth, you’re ready to decide which fertilizer is best for your lawn care needs. You may feel overwhelmed at all the different elements needed for a quality lawn that will make you the talk of the neighborhood, but there’s no reason to stress. Having a high-quality lawn just means understanding your lawn’s needs and finding the best fertilizer to meet those needs. After a while, you’ll be a pro at knowing which of the macronutrients for lawn health are necessary for your lawn care goals. 


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