What Height to Cut St Augustine Grass? Full Guide

To maintain a healthy St. Augustine lawn, we recommend cutting it to a specific height based on several factors. Our experience says that tailoring the mowing height to the season, grass condition, and mowing frequency can significantly enhance your St. Augustine lawn’s health and appearance.

Let’s explore and see.

What Height To Cut St Augustine Grass?

When cutting St Augustine grass, make sure to aim for a height of 2.5 to 3.5 inches. In shady areas, we suggest leaving an extra inch to promote stronger growth.

It’s better to mow St Augustine grass a bit shorter, around 2 to 2.5 inches. This helps reduce thatch buildup and prepares the grass for colder weather.

If your lawn is in a sunny area with good soil, you can let the St Augustine grass grow up to 4 inches. This encourages a lush, green look.

For areas with thin soil or more shade, keeping the grass at 3 to 3.5 inches is advisable. This height helps the St Augustine grass develop strong roots and outcompete weeds.

How to Measure the Mowing Height for St. Augustine Grass?

To measure the mowing height for St. Augustine grass, you can use a ruler or measuring tape, a lawn mower with adjustable height settings, or a specialized grass height gauge. Each of these methods ensures that you maintain the ideal length for the health and appearance of your lawn.

Using a Ruler or Measuring Tape

This method involves manually measuring the grass height with a ruler or measuring tape. Place the ruler vertically in the grass, and note the length of the blades from the soil to the tip. This straightforward technique helps in maintaining a consistent height, which is crucial for St. Augustine grass to develop a deep root system and withstand environmental stressors.

Regular measurement allows for precise adjustments to mowing routines, ensuring the grass remains at its ideal height of 3 to 4 inches.

Lawn Mower with Adjustable Height Settings

Modern lawnmowers often come with adjustable height settings, which are ideal for maintaining St. Augustine grass. Before mowing, adjust the mower’s setting to the desired height, typically between 3 to 4 inches for this type of grass.

This method provides a uniform cut, crucial for the grass’s health and aesthetic appeal. Consistently mowing at the right height encourages denser growth, reducing weed invasion and enhancing the lawn’s resilience against diseases and pests.

Specialized Grass Height Gauge

A grass height gauge is a specialized tool designed for measuring lawn grass height accurately. It’s particularly useful for St. Augustine grass, as maintaining the correct height is vital for its health. Place the gauge on the lawn to get an exact measurement.

This tool is especially beneficial for lawn care professionals or enthusiasts who seek precision. Regular use of a grass height gauge ensures that the St. Augustine grass is kept at an optimal height, promoting a lush, green, and healthy lawn.

What Are the Risks of Mowing St. Augustine Grass Too High or Too Low?

Both mowing St. Augustine grass too high and too low can have downsides for your lawn’s health and appearance. Please go through this chart.

St. Augustine Grass  Height	Risks	Details
Too High (> 4 inches)	Thinning and Patchy Growth	Tall blades overshadow lower shoots, leading to uneven lawn growth.
	Increased Weed Pressure	Tall grass creates open spaces for weeds to establish themselves.
	Thatch Buildup	Faster accumulation of dead grass clippings, suffocating roots.
	Risk of Fungal Diseases	Poor air circulation in tall grass promotes fungal growth.
	Pest Problems	Attracts pests like chinch bugs.
Too Low (< 2 inches)	Stressed and Weakened Grass	Short blades reduce photosynthesis, weakening the grass.
	Heat and Drought Stress	Less shade for the soil, increasing the risk of drying out.
	Increased Scalping Risk	Mower blades may scalp the soil, damaging the grass crown.
	Root Growth Inhibition	Continual cutting reduces energy reserves, weakening root systems.
	Unattractive Appearance	Very short lawns may appear brown and patchy.

When to Cut St Augustine Grass?

St. Augustine grass should be cut when it reaches about one-third higher than the desired mowing height, typically when it’s about 4 to 4.5 inches tall. This usually means mowing every 5 to 7 days during its active growing season in the spring and summer.

Consistent mowing at the correct height encourages a dense, lush lawn, enhances its green color, and reduces the likelihood of weed growth and pest infestations, ensuring optimal health and aesthetic appeal of your lawn.