Aerating your lawn is an important part of lawn care and maintenance. Aerating, sometimes called “core aeration”, involves punching holes into the soil to allow air, water and nutrients to better reach the grass roots. This helps reduce soil compaction and thatch buildup for a thicker, healthier lawn.
Many homeowners wonder if they should mow their lawn very short before aerating to allow the aerator tines to penetrate deeper into the soil. Here are the key considerations when deciding whether to mow short before aerating your lawn.
Quick Answers:
– Mowing short before aerating is usually recommended, such as lowering mower height by 1 setting or to 1-2 inches. This allows aerator tines better soil penetration.
– However, don’t mow extremely short right before aerating. Scalping the lawn increases stress and susceptibility to weed germination.
– Best practice is to gradually reduce mowing height over several mowings leading up to aeration day.
– Adjust mower deck to lowest recommended height for your grass type. Cutting too short can damage the lawn.
– Let grass recover for a few days after last mowing before aeration.
Should You Mow Short Before Aeration?
Mowing your lawn shorter than normal prior to aerating is usually recommended. A shorter mowing height allows the aerator tines to more easily penetrate through the grass and thatch layer down into the soil.
Longer grass can prevent the aerator from reaching the optimum depth for pulling cores from the lawn. Cores extracted from the soil are the key to the benefits of aeration. Long grass causes friction against the aerating machine tines, preventing them from digging deeply.
Lowering the mowing height before aerating makes it easier for the tines to extract deeper soil cores. Deeper aeration holes provide the following benefits:
Benefits of Lower Mowing Before Aeration:
– Alleviates soil compaction at greater depths
– Provides deeper channels for improved air circulation to roots
– Allows better water drainage through soil profile
– Enhances root growth farther down for a stronger lawn
– Provides deeper access to apply soil amendments like compost
– Maximizes the overall effectiveness of the aeration
How Short Should You Mow Before Aerating?
A general guideline is to mow your lawn about 1 to 2 inches shorter than usual leading up to aerating. For example, if you normally cut at 3 inches, then mow at 1 to 2 inches prior to aerating.
Lowering mowing height even more, such as scalping down to the very minimum height, can put added stress on the lawn. Extreme scalping right before aeration increases the potential for weed seed germination.
Rather than drastically scalping, best practice is to gradually reduce mowing height in the 2-3 weeks before aerating. This allows the grass plants to adjust without excessive shock.
On the last mowing before aerating, use the lowest recommended height for your specific grass type. This provides short access for tines while avoiding scalping damage. Allow grass to recover for a few days before aerating.
Recommended Last Mowing Heights Before Aeration:
| Grass Type | Last Mowing Height Before Aeration |
|---|---|
| Kentucky Bluegrass | 1.5 – 2 inches |
| Perennial Ryegrass | 1.5 – 2 inches |
| Tall Fescue | 2 – 2.5 inches |
| Fine Fescue | 1.5 – 2 inches |
| Bermuda grass | 0.5 – 1 inch |
| Zoysia grass | 0.5 – 1 inch |
These heights maximize aeration effectiveness for each grass type without excessively damaging the turf. Gradually mow down to these heights over several mowings before aerating.
Disadvantages of Mowing Too Short Before Aeration
While mowing shorter aids tine penetration, cutting too short just before aerating can be counterproductive:
– Scalping causes dramatic stress, increasing susceptibility to diseases, weeds and environmental damage.
– Grass needs time to recover from lowest mowing height before undergoing aeration damage.
– Excessive removal of leaf tissue reduces carbohydrate reserves and vigor
– Can expose soil to erosion, temperature extremes and moisture loss
– Increases potential for weed seed germination in bare areas
– Compromises the lawn’s overall appearance and health
For these reasons, never mow lower than the minimum recommended height for your grass type. Cutting closer than this threshold scalps the crowns and stems leading to decline.
Also, avoid mowing shorter than your normal height immediately before aerating. The shock of drastic mower height reduction plus aeration can seriously set back turf health.
Instead, gradually reduce mowing height to the ideal level in the weeks prior to aeration. This gives grass plants time to adjust to an increasingly shorter height before undergoing the aeration process.
When to Mow Short Before Aerating
Time the lowest mowing just before the period of aeration, but not immediately before. Here are some general timeframes:
– Make the last mowing at lowest height 5-7 days before aerating.
– Gradually reduce mowing height over 2-3 weeks leading up to the last mowing.
– For example, if aerating on Saturday, mow at lowest height the prior weekend.
– Mow at a standard height 2-3 days before aerating to clean up any stray clippings.
The week between final mowing and aeration gives grass time to recover before undergoing aeration. But mowing height will still be low enough for good tine penetration.
Avoid mowing on the same day as aerating. This piles on excessive stress. Let grass plants recuperate for a few days between mowing and aeration.
Also, don’t wait too long after last mowing to aerate. You want the height benefit of a shorter cut when those tines punch holes. Time the lowest mowing just before aeration for best results.
Cultural Practices Supporting Low Mowing Before Aeration
Certain lawn care practices leading up to low mowing will help minimize grass stress and optimize recovery:
– Fertilize 4-6 weeks before the planned aeration date, but not immediately before. Fertilizer promotes faster regrowth and recovery. But apply it well in advance of lowering mower height.
– Water deeply 1-2 days before the last mowing to hydrate the soil. This prevents drought stress when grass is cut short.
– Sharp mower blades make clean cuts rather than tearing leaf blades. Get blades sharpened or replaced before the lowest cut.
– Remove excessive thatch before gradually lowering mowing heights. Thick layers of thatch restrict grass access to moisture and nutrients.
– Allow longer grass clippings to disperse into lawn rather than removing them all. Clippings provide moisture retention and nutrients during regrowth.
Proper mowing practices and lawn care leading up to the lowest cut will ensure grass rebounds quickly. Aeration performed shortly after mowing short then provides maximum benefit.
Alternatives to Short Mowing Before Aeration
Some lawn experts advise aerating without mowing short first. They make the following points:
– Mowing short adds more stress on top of aeration damage.
– Aeration is effective even if grass is maintained at normal height.
– Core removal is still substantial despite less tine penetration depth.
– Short mowing risks scalping damage to lawn health.
If choosing not to mow at a lower height before aerating, here are some tips:
– Use a power rake or dethatcher to remove excess thatch so tines can penetrate soil.
– Select hollow tines that are longer to achieve better depth through taller grass.
– Make multiple passes in different directions with the aerator to increase hole quantity.
– Use a tractor-mounted aerator that can apply more weight and power into the ground.
While mowing short before aerating is commonly recommended, it’s not strictly necessary in all cases. Adjust practices based on your specific grass type, soil conditions and aeration equipment.
Best Practices for Mowing Short Before Aerator
Here is a summary of the best practices for mowing short before core aeration:
– Gradually reduce mowing height over 2-3 weeks leading up to aeration date.
– Make the last mowing at the lowest recommended height for the grass species – but avoid scalping.
– Time the lowest mowing 5-7 days before the scheduled aeration date.
– Allow grass to recover for a few days after last mowing before aerating.
– Use sharp mower blades to prevent tearing leaf blades at shortest height.
– Maintain proper irrigation, fertilization and thatch control for faster recovery.
– Consider alternatives if mowing short risks excessive damage to your lawn.
Proper mowing practices before aeration maximize tine penetration while minimizing lawn stress. Follow these guidelines to achieve the full benefits of core aeration for your soil type and grass species.
Conclusion
Mowing your lawn shorter before aerating is a recommended practice by most experts. A slightly shorter cut allows the aerator tines to punch deeper into soil for better core extraction. This enhances aeration benefits like compaction relief, drainage and rooting depth.
However, extreme scalping or mowing far below normal height can stress grass and cause decline. Best practice is to gradually reduce mowing height over several mowings leading up to aerating. On the final pre-aeration mowing, cut at the lowest recommended height for your specific turfgrass. Allow at least 5 days of recovery before performing core aeration. Proper mowing preparation coupled with smart aeration practices will build a healthier, thriving lawn.
