Gardening Landscaping Lawn Care

Grass Cutting Height Chart: How High to Cut Your Grass

Get Acquainted With the Settings on Your Lawn Mower Wheels

Ruler marking the grass height

The Spruce / Jayme Burrows

Finding the optimal grass cutting height is important to maintain your lawn’s health. If you mow the lawn too short it can damage your lawn. But cool-season grasses and warm-season grasses also require different cutting heights. Below, review our grass-cutting height chart for types of grasses and learn how high to cut grass in the spring, summer, and fall.

Grass Cutting Height Chart

Grass Type Height to Mow At  How High to Cut 
Tall Fescue 4-6 in. 3-4 in.
Fine Fescue 4-6 in. 3-4 in.
Kentucky Bluegrass 4-6 in. 3-4 in.
Perennial Ryegrass 4-6 in. 3-4 in.
Bermuda Grass 3-4 in. 2-2 ½ in.
St. Augustine Grass 3-4 in. 2-2 ½ in.
Centipede Grass 3-4 in. 2-2 ½ in.
Zoysia Grass 3-4 in. 2-2 ½ in.

Cutting Cool-Season vs. Warm-Season Grasses

Cool-season grasses should typically be cut to about 3 to 4 inches high. Warm-season grasses should typically be cut to about 2 to 2 ½ inches high. The common cool-season grasses include fine and tall fescue grass, Kentucky bluegrass, and perennial ryegrass. Common warm-season grasses include Bermuda grass, St. Augustine grass, centipede grass, and zoysia grass.

Never mow more than half of the lawn's total height. Cutting grass is similar to pruning plants and cutting too much removes the leaf surface where the plant can photosynthesize. If there is not enough leaf surface, your lawn’s root system will weaken as the plant uses up its stored nutrients. 

Tip

Bare grass patches can damage grass roots. It's best to repair cool-season grass bald spots by planting grass seed in the late summer and fall. Repair warm-season grass patches in late spring or early summer.

It is especially recommended that you stick to this rule of thumb in the fall (and, to a lesser degree, in spring, but see below). In summer, meanwhile, if you can't remember the measurements, err on the side of mowing at a greater height by choosing a higher setting on your lawnmower wheels when the weather is really hot or dry.

Red lawn mower on grass

The Spruce / Jayme Burrows

How High to Cut Grass in Spring

In the spring, cut cool-season grasses to 3 or 4 inches. Once your grass reaches a height of about 6 inches tall, it’s time to mow. Warm-season grasses should be cut to 2 or 2 ½ inches, and you'll know it’s time to mow once these grasses reach about 4 inches tall.

Grass starts growing quickly in the spring, especially after rain, and can be cut shorter at the beginning of the growing season to help remove winter debris and encourage new growth. It's tough to know how often to mow because it depends on several factors, including rainfall amounts, grass type, and soil health.

How High to Cut Grass in Summer

In the summer, keep both cool-season and warm-season grasses slightly taller. Cut cool-season grasses to 3 or 3 ½ inches. Mow warm-season grasses to 2 or 2 ½ inches. In summer, grass can be kept a bit higher to prevent weeds, help shade the soil line, and maintain water in the soil.

How High to Cut Grass in Fall

Cool-season grass can be mowed down to about 2 ½ inches before winter's first frost. Warm-season grasses can be cut to 1 ½ or 2 inches in the fall before cooler weather appears.

In fall, grass should be cut to a medium length to keep it at a reasonable height over winter but to keep the roots protected during winter. Finding that right height is a little tricky because grass that's too tall in the winter tends to become matted and prone to diseases.

A Trick to Help You Remember These Measurements

Draw a line across one of your lawn mower tires that stands 3 2/3 inches above surface level. Draw an arrow, as well, to indicate which direction is up/down. That way, you'll see where the grass level stands in relation to the line so you'll know when and how much to mow your lawn. It can take some experimenting to see what mowing height you need to set your mower to and then you can mark that slot to find it quickly.

FAQ
  • How do I know what height my mower is set to?

    Different types of mowers have different ways to set the height so it's best to consult your owner's manual. You can typically use the mower's levers or gears to set the correct height according to the type of grass you have.

  • What is the 1 out of 3 rule for mowing my grass?

    The 1 out of 3 rule refers to the preference that you should never cut more than 1/3 of the grass blades every time you mow your lawn. For example, if you are cutting your lawn and it has grown 3 inches tall, do not cut more than 1 inch off of the blade, which is 1/3 of the total height. Cutting only 1/3 of the blade keeps the grass healthy without damaging its growth.

  • Is it better to keep grass long or short in summer?

    One of the biggest mistakes people make is mowing the grass too short in the summer. Keep the grass slightly longer in the summer so the longer blades can protect the roots from the harsh summer sun.

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  1. The UC Guide to Healthy Lawns. University of California Agriculture and Natural Resources.