What Nutrients Do Plants and Lawns Need?

By Jaime Staufenbeil - Milorganite Agronomist
April 2, 2022

A well-balanced diet provides the nutrients you need to live a healthy life. There are consequences when you’re not getting enough of one nutrient or another. Plants also need a well-balanced, nutritional diet. Plants and lawns decline when they're not getting the nutrients they need and can lead to disease and other issues.

Plants use nutrients they find in the air and soil to grow. Unfortunately, most soils don’t have everything plants need. It’s like looking in your refrigerator and finding only apples. They’re good for you, but they’re not going to provide everything you need to be healthy. It’s similar to plants trying to survive on a diet of only one nutrient.

When plants aren’t getting the balanced diet they need, it’s time to provide a supplement, and fertilizer is the most convenient way to improve the health of your plants.

You’ll find a series of three numbers on every bag of fertilizer. The three numbers on fertilizer bags indicate the percent of each nutrient in the bag, in the same order as N-P-K. The analysis for Milorganite, for example, is 6-4-0, which guarantees there’s 6% nitrogen, 4% phosphorus, and less than one percent potassium in the bag. The analysis is regulated, so rest assured, it’s accurate.

What nutrients does my lawn need?

Your balanced meal could include reasonable portions of protein (steak), starch (baked potato), and vegetable (green beans). (Beer is optional.) Your lawn’s meal would include N-P-K. The question is, how much of each nutrient does it need?

You can’t ask your lawn directly why it needs N-P-K, but there’s a way to find out: test the soil.

We recommend having your soil tested to find out how much of each nutrient is already in the soil. We also realize most people don’t have their soil tested. We wish they would, but it’s just the way it is.

If we could just convince you that it doesn’t take that much work, will likely cost you less than $20, and you’ll be better able to nurture a beautiful, healthy lawn. Do a search for your state’s county extension offices and “soil testing.” Here’s a resource that can get you started. With the test results in hand, you‘ll know what nutrients your soil lacks to keep your lawn well fed. “Too much of a good thing” is possible with plants, and can be detrimental to your lawn and the environment.

Here’s a quick rundown of what each of the three essential nutrients does for plants.