This is a common question for homeowners and groundskeepers alike. The height at which you mow your lawn can have an impact on how quickly it regrows and how healthy it is overall. In this article, we’ll explore the science behind grass growth, the pros and cons of mowing short, and best practices for promoting fast, lush regrowth.
The Basics of Grass Growth
Before we can answer whether short mowing leads to faster regrowth, it’s helpful to understand some basics about how grass plants grow. There are a few key factors that influence the rate of grass growth:
- Nutrients – Fertilizing provides nitrogen, potassium, and phosphorus that facilitate rapid growth. Grass can’t regrow quickly without adequate nutrition.
- Moisture – Grass needs water to support growth. Adequate rainfall or irrigation is key when trying to maximize regrowth.
- Temperature – Warm seasons promote faster regrowth. Cooler temperatures slow down growth.
- Light – Sunlight provides energy for photosynthesis and growth. Shady lawns see slower regrowth.
In addition to these environmental factors, the grass species itself also influences regrowth rate. Grass types like Kentucky bluegrass and perennial ryegrass regrow quickly, while Bermudagrass and zoysia are slower to recover.
The Case for Mowing Short
Proponents of mowing short make some compelling arguments:
- Removes stem and leaf tissue – By mowing short, more of the grass stem and leaf tissue is removed. The plant responds by activating new growth at the crown.
- Reduces competition – Short mowing means less leaf surface competing for light. Remaining leaves can absorb more sunlight to power growth.
- Prevents thatch buildup – Thatch is a layer of undecomposed stems and roots between soil and green growth. Mowing short helps reduce excess thatch.
- Encourages dense turf – Frequent short mowing signals to the grass to produce more tillers (shoots). This can create a thicker, denser lawn.
These factors suggest that maintaining a short cut could promote faster regrowth. The grass plant works to quickly replace leaf tissue lost to mowing and devotes energy to vertical growth.
The Case Against Mowing Too Short
However, there are also good arguments to avoid mowing too short:
- Stress on the grass – Removing too much leaf surface leads to greater moisture loss. This can stress the plants.
- Reduced photosynthesis – With less leaf area, the grass has less ability to produce the sugars needed for regrowth via photosynthesis.
- Weakened crowns – Cutting too low risks damaging the crowns (the base of the shoots), which can impair regrowth.
- Root damage – Severing a large portion of leaf mass starves roots. It can reduce rooting depth and health over time.
- Weed vulnerability – Thinning the turf opens areas for weeds to establish. Weeds compete with grass for resources.
Mowing too aggressively to a very low height could shock the grass plants and do more harm than good.
Best Practices for Optimal Regrowth
Most turfgrass experts recommend a happy medium when mowing – not too long and not too short:
- Mow at the highest recommended height for your grass type. This provides adequate leaf surface for growth.
- Only remove 1/3 or less of the grass blade per mowing session. Small, frequent cuts are ideal.
- Keep mower blades sharp. Ragged cuts from dull blades are more stressful to the grass.
- Allow at least 2-3 days between mowings for recovery and regrowth.
- Fertilize and irrigate as needed to provide optimal nutrients and moisture.
- Adjust cutting height through the seasons. Mow shorter in fall/winter, higher in spring/summer.
Adhering to these best practices will ensure your lawn gets trimmed often enough to encourage thick, dense growth while minimizing stress to the plants. Let’s look at how this plays out over a typical growing season.
Sample Regrowth Timeline
Here is an example timeline of regrowth you could expect following proper mowing practices:
| Date | Action | Expected Regrowth Time |
|---|---|---|
| Early spring | Raise mower height up 1 notch (e.g. from 2″ to 3″) as temperatures warm up. | 7-10 days |
| Mid spring | Mow at height recommended for the grass species during rapid growth periods. | 4-6 days |
| Early summer | Maintain mowing height through summer, watering as needed. | 4-7 days |
| Mid summer | Avoid mowing during heat waves/drought stress. | 7+ days |
| Late summer | Resume normal mowing schedule, fertilize to boost growth. | 4-6 days |
| Early fall | Lower mower height by 1 setting as growth slows. | 7-10 days |
| Late fall | Continue mowing until grass stops growing. | 10+ days |
These are general estimates – actual regrowth rates will vary based on grass type, weather, and care. But following proper mowing practices should bring the turf back within 5-7 days during peak growing seasons.
Signs You’re Mowing Too Short
Some indicators that you may be cutting your grass too short include:
- Seeing brown, dead tips on the grass blades a few days after mowing.
- Noticing excessive wilting, curling, or bluish-green hues indicative of drought stress.
- Soil is visible through thin turf in many spots.
- Weeds invading bare areas that were previously grass.
- Grass taking much longer than normal to regrow – 10+ days.
- Seeing damage to the crown and stolons (runners) upon close inspection.
If you observe any of these warning signs, try raising your mower height incrementally to find the optimal cutting length where grass recovers vigorously in 5-7 days.
Special Cases for Shorter Mowing
While moderate cutting heights are best for most lawns, there are some exceptions where ultrashort mowing makes sense:
- Greens and tees on golf courses – These areas are mowed very low (0.125″-0.25″) for optimal ball rolling and playability.
- Sports fields – Close mowing provides dense, durable turf for sports like football, soccer, and baseball.
- Ornamental lawns – Some homeowners prefer a manicured, putting green aesthetic and don’t mind high maintenance.
- New seedings – Freshly seeded lawns should be mowed short to remove clippings and encourage tillering.
In these cases, aggressive mowing heights make sense despite reduced regrowth rates. The turf in these settings receives ample fertilizer and irrigation to stay healthy under close mowing. Home lawns generally don’t justify the ultra-short look.
Conclusion
Finding the ideal mowing height is a balancing act – short enough to encourage dense, thick turf, but not so short that it starves the lawn of needed leaf surface area. For most home lawns, following the one-third rule by cutting no more than one-third of the blade length and maintaining manufacturer recommended heights for the grass type will provide the fastest regrowth rates.
It’s important to also fertilize and irrigate sufficiently, sharpen mower blades regularly, and adjust heights to account for seasonal needs. With proper practices, cool season grasses can rebound in as little as 4-6 days during peak growth. Allowing the lawn adequate recovery time between mowings is just as crucial as the cutting height itself.
In summary, moderate mowing heights of 2-4″ designed around the needs of your specific lawn will generate faster regrowth compared to drastic scalping. Find the goldilocks zone for your grass type where the turf looks tidy but remains healthy enough to revive rapidly after being cut. With a little trial and error, you can balance aesthetics and performance to craft a lush, resilient lawn.
