Does cutting the grass make it grow thicker and lusher? This is a common gardening myth that many homeowners swear by. The quick answer is no, frequent mowing does not directly cause grass to become thicker. However, the right mowing practices can promote thicker, healthier grass growth over time. Cutting grass too short or too infrequently can thin it out, while following proper mowing techniques encourages dense, vigorous turf. Read on to learn the science behind lawn growth and the best mowing schedule for a thick, green lawn.
How Does Grass Grow?
Grass consists of individual plants called tillers that grow vertically from crown tissue at the base. The more active tillers in a grass plant, the thicker and denser it will be. Each tiller has a growing point at its base that produces new leaves. Mowing removes the top portion of tillers, cutting off the leaves and stem above this growing point. As long as at least 2-3 inches of leaf blade remains after mowing, the tiller will recover and continue growing. If too much is removed, the tiller may die.
Factors That Affect Tiller Growth
Several factors influence tiller production and density:
- Genetics – Grass species and varieties have inherent differences in tiller density. For example, fine fescues naturally grow in thick tufts while bermudagrass has a more spreading growth pattern.
- Environmental conditions – Tillering increases in ideal growing conditions with adequate moisture, sunlight, and nutrients. Heat, drought, shade, or poor nutrition leads to thinner grass.
- Mowing height – Cutting height significantly impacts tiller density. Maintaining an optimal height for the grass type encourages lush, thick growth. Cutting too short or infrequent mowing causes thinning.
- Season and growth cycle – Cool weather grasses produce more tillers and grow more slowly in spring and fall. Hot summer grasses are at peak density in summer months.
The growth cycle and mowing practices have the biggest influence on tiller production and thickness.
Does Cutting Grass Make It Grow Thicker?
Many gardeners notice grass seems to thicken up after mowing. But simply cutting the grass does not stimulate new growth from the base. Removal of leaf tissue does not change the inherent genetic growth pattern of the grass. However, proper mowing practices allow grass to maximize its natural growing ability. Here’s a look at why mowing improves thickness over time:
Removes Dead Material
Mowing removes the upper portion of grass leaves that are no longer actively growing. The cut leaves and stems break down to provide nutrients that support new growth. Regular mowing prevents a buildup of old material that can shade out new leaves. Removal of dead stems and leaves allows more sunlight to reach the base of the plant and growing points to encourage new tiller production.
Stimulates Tillering
When mowing removes part of the leaf but leaves enough behind, the plant responds by producing new tillers and accelerating growth. This compensates for the lost leaf tissue. Grass plants that are infrequently mowed will dedicate energy to growing taller between cuttings rather than producing more tillers at the base.
Encourages Deeper Roots
Consistent mowing at the proper height trains grass plants to grow shorter, stockier leaves and invest more resources in deeper root growth. Longer leaf blades lead to shallow roots. But when the top growth is regularly trimmed back, plants divert energy into growing deeper, thicker roots. Stronger roots support more vigorous leaf and tiller development.
Allows More Uniform Growth
If grass gets too tall between mowings, shading occurs at the base. The upper leaves hog sunlight while the bottom leaves decline. Regular trimming prevents shading and keeps all leaves growing at the same rate for denser growth. It also exposes soil to warmth and light to activate soil microbes and nutrient release.
Reduces Stress
Cutting off up to 1/3 of total leaf blade causes minimal stress to plants. Infrequent severe cutting shocks the grass, using up energy reserves and reducing growth. Smaller increments of mowing are less taxing. Grass recovers quicker and can devote resources to new leaf and tiller growth.
Improves Air Circulation
Tall grass blocks airflow close to the soil. Regular trimming creates space between leaves for better circulation. Improved air movement reduces disease problems and helps soil dry out from irrigation, rain, or dew. Good airflow is key for healthy turf.
Proper Mowing Techniques
To maximize tiller production and thickness, follow these proper mowing practices:
Mow at Recommended Heights
Each grass species has an optimal cutting height:
| Grass Type | Mowing Height |
|---|---|
| Bermudagrass | 1-2 inches |
| Zoysia | 2-3 inches |
| St. Augustine | 3-4 inches |
| Fescue | 3-4 inches |
| Bluegrass | 2.5-3.5 inches |
| Ryegrass | 2-3 inches |
Never cut off more than 1/3 of total blade length at one mowing. For example, if the grass is 4 inches, don’t mow below 3 inches.Cutting too short causes thin, weakened turf.
Mow Frequently
During active growing seasons, mow every 4-7 days. Frequent light mowing is better than occasional heavy cutting. Avoid removing more than 1 inch of growth at each mowing. Waiting longer means cutting too much at once, which is stressful.
Leave Clippings
Leave chopped grass blades on the lawn to break down and release nitrogen. Clippings do not contribute to thatch buildup. This “grasscycling” reduces fertilizer needs by up to 25%.
Change Directions
Alter mowing patterns each time to avoid wear from wheels repeatedly turning the same way. Varying directions prevents soil compaction and ruts that damage grass.
Avoid Wet Grass
Mowing when grass is wet risks pulling blades out rather than cutting them cleanly. Wait until turf is dry to mow for a clean cut. Wet grass also clumps on the mower deck.
Sharpen Blades
Use a sharp mower blade to prevent tearing leaf tips. Jagged cuts turn brown and damage plants. Sharp blades make clean cuts that heal quickly.
Adjust Cutting Speed
Move mower at a steady, moderate pace. Going too fast reduces cutting quality. Slowing down prevents missed spots and strips. Proper mower speed ensures an even cut.
When To Avoid Mowing
Certain conditions call for postponing mowing:
- Cold temperatures – Mowing when grass is dormant in winter or during cold snaps can damage plants. Wait for growth to resume in spring or warmer weather.
- Heat and drought – During hot, dry periods, mowing adds more stress. Allow grass to go dormant and raise mowing height until temperatures cool and moisture returns.
- Disease outbreaks – Hold off mowing when fungal disease is present to avoid spreading spores. Remove clippings promptly if mowing cannot wait.
- Too much growth – Letting grass get overly tall then attempting to cut more than 1/3 of blade leads to an uneven appearance. Make more frequent passes at normal heights to catch up.
Avoid mowing grass when it’s under stress or unhealthy to prevent further decline. Time mowing carefully based on current growing conditions.
Overseeding for Thicker Grass
In addition to proper mowing, overseeding thin or damaged areas in spring and fall helps fill in bare spots for a thicker lawn. Overseeding steps include:
Prepare Soil
Loosen soil surface with a rake or power dethatcher. Remove debris and break up compaction to allow seeds close contact with soil.
Apply Starter Fertilizer
Use a balanced starter fertilizer to provide new seedlings with nutrients for strong establishment and growth.
Spread Seed
Select a grass seed variety well-suited to your climate. Sow at recommended rates. Often slit seeders work better than broadcast spreaders to ensure good contact.
Cover Lightly
Rake lightly over seeds or roll the area to settle them into soil. Don’t bury too deep. Grass needs light to germinate.
Water Frequently
Keep seeds moist, but not saturated, until sprouted. Once established, reduce watering to normal levels.
Reduce Traffic
Avoid foot traffic or mowing on newly seeded areas until the grass reaches mowing height.
Overseeding fills in thin lawn areas to create a thicker, lush turf. Combine with proper regular mowing to maximize density.
Conclusion
Mowing practices do not directly cause grass to grow thicker. But maintaining proper cutting height and frequency allows grass plants to maximize natural tiller production and growth density over time. Following recommended mowing guidelines tailors lawn care to the grass type for optimal health and thickness. Avoiding overcutting, mowing during stress, and leaving clippings enhances density. Overseeding thin spots also improves overall lawn thickness. With the right mowing schedule and care, homeowners can achieve a lush, thick landscape.