Grass 101: How Deep Do Grass Roots Grow?

Susan McCullah
Written by Susan McCullah
Updated May 11, 2022
A boy looking at blooming flowers in the house’s yard
Photo: twomeows / Moment / Getty Images


  • Grass roots can grow from 4 inches to as deep as 8 feet.

  • Deep grass roots transport vitamins, minerals, and moisture.  

  • Different types of grass have different root depths.

  • Brown grass and thin patches are signs of shallow roots. 

  • Lawn care like mowing and watering helps grass roots grow deeper.

Get quotes from up to 3 pros!
Enter a zip below and get matched to top-rated pros near you.

If you’re planning on making your grass green and lush this year, you’ll need to pay special attention to your grass root system. Understanding the fundamental role the roots play, how deep they grow, and how they can grow deeper will go a long way toward growing a healthy lawn. Let’s dig into some grass roots. 

How Deep Do Grass Roots Grow?

Grass roots are usually between six inches and two feet. Any homeowner who has dug in the yard has come across them. They’re white, dense, clumped together, and look stringy. Root depth depends on several factors like the type of grass, soil health, and lawn care maintenance schedule. 

Why Are Deep Grass Roots Essential?

Your lawn’s root system is what carries nutrients, water, and oxygen to nourish your grass. The stronger and deeper the root system, the healthier the grass. Deep roots provide the following benefits for your lawn: 

Provide More Nutrients

When you’re watering your lawn or it rains, the water seeps down into the ground’s subsoil. It carries nutrients with it deep into the soil. A deep root system soaks these vitamins and minerals up and uses them to grow. 

Shallow grass roots can only soak in nutrients from the top few inches of soil. This causes them to miss out on the rich nutrients located deeper in the ground. Grass with shallow roots won’t be as well-nourished as its deeply-rooted counterparts.

Make Your Turf More Durable

Sometimes Mother Nature is hard on your lawn. Heavy rain and wind, droughts, snow, and scorching temperatures can damage. Deep roots help protect your grass during these stressful situations:

  • Drought Stress: Deep roots have more access to moisture deep in the soil that shallow roots can’t reach. 

  • Freezing Temperatures: Shallow roots are closer to the ground, making them more likely to die during deep cold snaps. 

  • Erosion: A robust, deep root system better holds soil in place. 

Break Through Compacted Soil

Soils like clay soil may compact, making it more difficult for grass to get nutrients. Deeper roots break paths in the soil for water and nutrients to penetrate. 

Allow New Roots to Generate 

Roots eventually get old, die, and turn into nutrients for new roots. Deep-root growth gives new roots a chance to grow faster and stronger than shallow roots.

How to Measure Your Lawn’s Root System

Use a gardening spade to dig a small hole through the soil surface to the bottom of your grass roots. Eyeball them to see how long they are. If they are just a few inches into the ground, your lawn grass has shallow roots. 

What Are the Signs of Shallow Roots?

Your grass will show distinct signs if its roots haven’t grown deep enough.  If you notice these issues, address them yourself or call a local landscaping pro to come out and look at them for you. 

  • Thin turf

  • Looks dry almost all the time

  • Brown edges around the yard

  • Brown patches

  • Grass pulls up easily

How Can You Make Your Grass Root System Grow Deeper?

With a little planning and time, you can promote deeper grass root growth with a diligent lawn care routine throughout the year.  

Mowing Correctly

A teen boy mowing the grass in the garden
Photo: Cavan Images / Cavan / Getty Images

If you mow your grass blades too close, the plant will have trouble converting sunlight, water, and oxygen into food and energy. The grass will be too busy growing above ground to devote energy to root development.

When you mow, your grass thinks it’s under attack, causing roots to go deeper to sustain new growth. Over time, mowing helps create deeper, thicker roots.

Never cut over a third of your grass turf when mowing your yard. Leaving your grass a bit longer gives it plenty of time to absorb sunlight and shades the soil so it can retain water longer. 

Aerating Consistently

If you don’t already, add aeration to your lawn care regimen in the spring. It promotes healthy soil and makes sure air, water, and every nutrient possible make it to your plant roots. In addition, aerating your soil breaks up compacted soil, paving an easier path for deeper grass root growth. 

Not sure you want to tackle aerating your lawn yourself? Call a local aeration pro to help you get the job done. 

Watering Regularly

Watering your grass the right way is one of the most critical parts of your lawn care. If you’re wondering how often you should water your lawn, don’t water it daily. Overwatering can cause plant roots to stay in the top few inches of soil instead of reaching deeper into the ground in search of water. 

Schedule your lawn watering for two to three times weekly in the early summer and fall, and three times in the heat of the summer. Thoroughly soak your soil to encourage deep-root growth. Keep an eye on your yard, so it doesn’t dry out too much. Water in the morning so your soil has extra time to absorb the moisture before the sun zaps it.

Fertilizing Properly

In late fall, consider how to fertilize your lawn to help it stay healthy and promote root growth during the cold weather. Look for a weed and feed formula that nourishes the grass and helps with weed control. Fertilizing helps plant roots grow deeper and sets your grass up to be beautiful and healthy next spring.

Which Types of Grass Grow the Deepest Roots?

You can use many types of grass to create a lush lawn. Your choice should depend on the climate you live in and the type of soil you’re working with. Choose from either warm-season grasses or cool-season grasses. 

Warm-Season Grasses

These grasses grow best during the hottest times of the year. They look great in yards where the weather is hot and dry. 

  • Bermuda grass offers great heat and drought tolerance. Its root system can grow 6-feet deep or more. However, most of its roots are in the top 6 inches of soil.

  • Bahia grass is another popular drought-resistant turf. Its roots can grow 8-feet long, making it a hardy and durable lawn choice. 

  • St. Augustine is a coarse, warm-season grass. Its root depth averages 6 inches, so it’s one of the least-hardy warm-season grasses. 

Cool-Season Grasses

Cool-season grasses thrive in northern climates and lower temperatures. Their root depths are key to their appearance and durability. 

  • Kentucky bluegrass can withstand cold winters and looks divine. Depending on the watering schedule and the soil makeup, its root system will be 4 to 8 inches deep

  • Perennial ryegrass is a widely-used turf. Its roots are more shallow than other cool-season grasses, typically growing 4 to 6 inches deep

  • Tall fescue boasts the deepest roots of any cool-season grass, sometimes reaching depths of 2 to 3 feet.

Need professional help with your project?
Get quotes from top-rated pros.