Last Updated on October 15, 2025 by Duncan

Conflicting gardening advice abounds on the internet, particularly when it comes to knowing the right height to mow your grass before winter. If you are asking, is 2.5 inches too short for cool-season grass?

No, it’s not. Experts recommend cutting cool-season grass to 2.5 to 3 inches. For the warm-season grass, it can do best at 1.5 to 2 inches.

Perennial ryegrass, Kentucky bluegrass, and tall and fine fescue grass are the most common cool-season grasses. While centipede grass, zoysia grass, St. Augustine grass, and Bermuda grass are examples of common warm-season grasses.

Why does grass height matter?

Balance is necessary for everything, even your grass. Scalping, or cutting your grass too short, stresses your lawn and can cause bare spots, poor growth, or obvious damage.

Additionally, grass with scale may be more susceptible to weeds, many of which need extra attention to control.

While this is the case, allowing your grass to grow unchecked is not the best option. In addition to being unsightly, overly tall grass can attract pests and cause your lawn’s general health and thickness to deteriorate. It’s truly a balancing act, and you need to be smart about how you go about it.

To be on the safe side, you should never cut the lawn shorter than half of its height. Cutting too much grass eliminates the leaf surface where the plant can photosynthesize, which is comparable to over-trimming plants.

The root system of your grass will deteriorate as the plant depletes its stored nutrients if there is insufficient leaf surface.

How high should the grass be cut in spring?

Trim your cool-season grasses to 3 to 4 inches in the spring. It’s time to mow your grass when it’s around six inches tall. When warm-season grasses grow to a height of approximately 4 inches, it’s time to mow. Trim warm-season grasses to 2 or 2 ½ inches.

You can trim grass shorter at the start of the growing season to help clear winter detritus and promote new growth since it grows quickly in the spring, especially after rain.

Knowing how frequently to mow is difficult because it depends on a number of variables, such as soil health, grass type, and rainfall levels.

How high should to cut the grass in the fall?

Before the first frost of the winter, you can cut cool-season grass down to about 2 ½ inches. Before cooler weather arrives in the fall, trim warm-season grasses to 1½ to 2 inches.

Cutting the grass to a medium length in the fall will maintain it at a manageable height throughout the winter while also protecting the roots. Because overly tall grass becomes tangled and more susceptible to illnesses in the winter, it can be challenging to find the ideal height.

Work with a professional to guide you through.

How high should to cut the grass in summer?

You should keep both warm-season and cool-season grasses a little taller throughout the summer. Trim cool-season grasses to 3 or 3 ½ inches.

For the warm-season grasses, mow to 2 or 2 ½ inches. To help shade the soil line, keep water in the soil, and keep weeds out. Remember that you can keep the grass a little higher in the summer.

Mowing tips for a healthy lawn

When cutting the grass, there are a few things you can do to prevent overtaxing your lawn in addition to mowing it to the right height. To help encourage a flourishing, healthy grass, heed these tips:

• Make sure the blades on your mower are sharp. The grass may become fragile and susceptible to disease if dull blades rip it to shreds.
• Steer clear of mowing when it’s really hot or dry.
• Every time you mow, switch up your approach to avoid compaction of the soil or tire damage.
• To help your lawn get more nutrients, leave grass clippings on it.

FAQs

How can you determine the height at which your lawnmower is set?

It’s recommended to refer to your owner’s manual, as different mower types have different methods for adjusting the height. Depending on the kind of grass you have, you can usually adjust the mower’s height using its levers or gears.

When it comes to mowing your lawn, what is the 1 out of 3 rule?

When you mow your lawn, you should never cut more than one-third of the grass blades. This is known as the “1 out of 3 rule.” If your grass has grown three inches tall, for instance, and you are cutting it, don’t cut more than one inch—or one-third of its height—off the blade.

The grass remains healthy without causing harm to its growth when only one-third of the blade is cut.

Is it preferable to have long or short grass throughout the summer?

In the summer, cutting the grass too short is one of the most common mistakes individuals make. In order to shield the roots from the intense summer heat, keep the grass a little longer in the summer.