How to Mow Tall Grass With a Push Mower Right
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How to mow tall grass with a push mower comes down to one rule: never remove more than one-third of the grass blade in a single mowing. If the grass is much taller than your deck can cut at once, take the first pass at the highest setting, then lower the deck over later mowings instead of cutting the lawn down in one go. A sharp blade, dry grass and a plan for clippings make the job easier and keep the lawn healthier.
Quick answer
- Cut no more than one-third of the grass blade at any one mowing (UW-Madison Division of Extension).
- For most lawns, keep the grass between 2.5 and 3.5 inches tall (UW-Madison Division of Extension and North Dakota State University Extension both give this range).
- Use a sharp blade, because dull blades tear the tips of the grass (North Dakota State University Extension).
- When grass is excessively tall, collect the clippings, since they can gather in clumps on the lawn (North Dakota State University Extension).
Why the one-third rule matters more with tall grass
Tall grass tempts people to set the deck low and cut everything off at once. The University of Wisconsin-Madison extension guidance warns against that. Removing more than one-third of the leaf tissue at one time makes turf more vulnerable to stress and pests, slows regrowth, and lets light reach the soil, which can encourage weed seeds to germinate. Its example is simple: if the turf is 4 inches tall, set the mower no lower than 2.5 inches.
North Dakota State University Extension uses the same principle with a different example. At a 3-inch cutting height, mow once the grass reaches no more than 4.5 inches. Both sources describe the same idea from two directions: the height you set should match the height the grass already is, and the mower should not take off more than a third in any single pass.
This is why a very tall lawn usually needs more than one mowing. The rule does not change because the grass is tall. It only means the work is spread across more passes.
A step-by-step approach for tall grass
Start by measuring the grass in several spots, not just one. The tallest patches set the pace, and the mower should not be asked to cut all of them down in one pass.
- Set the deck high. Raise the cutting height first, so that the first pass removes no more than one-third of the blade.
- Mow dry grass when you can. North Dakota State University Extension advises mowing when the grass is dry, which reduces clumping and produces a finer mulch.
- Check the blade. North Dakota State University Extension says sharpen or replace the blade about once a year, depending on how much you mow. Dull blades tear the tips of the grass.
- Collect clippings on very tall grass. If the grass is excessively tall, the same source advises collecting the clippings rather than leaving them on the turf.
- Lower the deck in steps. On later mowings, drop the setting a notch at a time until the lawn reaches the 2.5 to 3.5 inch range that both extension sources recommend.
Stepping down is the practical result of the one-third rule. Each mowing should cut a smaller share of the blade than the last, so the grass has time to recover between passes.
Push mower heights and what the listings say
Cutting height range is the first spec to check when your grass is tall. The table below uses only the height figures and features stated in each listing. Where a listing gives a range in its bullets and a different range in its specifications, the bullet figure is shown and the difference is noted.
| Listing | Type | Height settings in the listing | Notes the listing gives |
|---|---|---|---|
| YHUBHSIS 14-Inch Push Reel Lawn Mower | Manual reel, 5 blades | 0.6 to 1.8 inches, adjustable | Bullets say it cuts grass up to 7.5 inches tall. Its highest setting is 1.8 inches. |
| Walensee 16-Inch 5-Blade Push Reel Lawn Mower | Manual reel, 5 blades | 4 positions, 0.6 to 1.5 inches | Bullets say to trim taller grass in stages for best results. |
| Sun Joe MJ502M Manual Push Reel Lawn Mower, 20-Inch | Manual reel, 5 blades | 9 positions, up to 2.44 inches | Includes an 8.5-gallon grass catcher. |
| Hoteche 10-Amp Corded Electric Lawn Mower | Corded electric | 3 positions, 1 to 2.2 inches in the bullets | Bullets include a 30L grass bag. The specifications list a different range, 1.1 to 2.6 inches, which the listing does not reconcile. |
| DORTALA Corded 14-Inch Electric Push Mower | Corded electric | 3 positions: 1, 1.8 and 2.5 inches | The grass collection box can be detached for mulching. |
| Goplus 13-Inch 2-in-1 Electric Lawn Mower | Corded electric | 3 levels: 1, 1.6 and 2.2 inches | Bullets say the 30L collection box can be attached for collecting or removed for mulching. |
| Litheli 14-Inch Cordless Lawn Mower Without Battery | Battery, bare tool | 5 positions, 1 to 2.5 inches | The listing states that the battery and charger are not included. |
| CRAFTSMAN V20 20-Inch Push Mower | Battery push mower | Dual-lever adjustment, 1.5 to 3.5 inches | Specifications list 2 batteries and 2 chargers included. |
| Sun Joe MJ500M Manual Push Reel Lawn Mower | Manual reel | 4 positions, 0.88 to 1.81 inches | Bullets say performance may be limited on uneven terrain. |
What the table means for tall grass
The highest setting on the first reel mower in the table is 1.8 inches. Grass that stands 7.5 inches tall would need a deck set about 5 inches high to follow the one-third rule in a single pass, so that mower cannot do the first cut in one pass. The listing says it cuts grass up to 7.5 inches, but the one-third rule says that grass should be brought down in several mowings. The same logic applies to the other reel mowers in the table, which top out at 1.5 to 2.44 inches.
Walensee’s bullet is the most direct guidance from any listing: trim taller grass in stages. That matches the one-third rule. The Sun Joe 20-inch reel model has the highest top setting among the reel mowers listed, at 2.44 inches, and a 9-position lever gives finer steps between settings.
The corded electric and battery models have higher top settings in some cases, but the listing does not state how much grass each one can cut at a single setting. For a battery model such as the CRAFTSMAN V20 with a 1.5 to 3.5 inch range, the setting that matches the one-third rule depends on how tall the grass is at that moment. Check the grass first, then pick the setting.
Materials and build notes
Most listings in the table use plastic or alloy steel for the body and blades. The Walensee listing says it uses high-hardness alloy steel blades that are precision-ground for sharpness. The Sun Joe reel listing describes sharp, hardened steel blades. The Hoteche listing describes a laser-cut steel blade. For tall grass, blade sharpness matters more than the material name, so keep the blade sharp whichever model you choose.
Reel mowers do not require gas, oil or electric power. The listings say so directly, and that point matters for lawn owners who mow early in the morning. The listings do not state how long a blade will stay sharp in tall grass.
Mistakes to avoid when mowing tall grass
- Setting the deck too low on the first pass. This removes more than one-third of the blade and stresses the turf, according to the Wisconsin extension guidance.
- Mowing wet grass. Wet grass clumps, and North Dakota State University Extension advises mowing dry grass to reduce clumping.
- Leaving heavy clippings on the lawn. Excessively tall grass can smother the turf when clippings gather in clumps.
- Using a dull blade. Dull blades tear the tips of the grass, according to North Dakota State University Extension.
- Assuming a single pass will do. The one-third rule means a very tall lawn usually needs several mowings.
FAQ
How much of the grass blade can I cut at once?
No more than one-third of the leaf tissue at any one mowing, according to the UW-Madison Division of Extension. If the grass is 4 inches tall, the deck should be no lower than 2.5 inches for that pass.
What height should I set for a normal lawn?
Both university sources recommend a range of about 2.5 to 3.5 inches for most lawns. The Wisconsin guidance says higher settings suit lower-input lawns, and that low-maintenance lawns can be kept at about 3 to 4 inches.
Should I bag or mulch tall grass?
North Dakota State University Extension advises collecting clippings when the grass is excessively tall, because they can clump and smother the turf. Two listings in the table, the DORTALA and Goplus models, say the collection box can be attached for bagging or removed for mulching, so either approach can work with those models.
Why does mowing dry grass matter?
North Dakota State University Extension says dry grass reduces clumping and produces finer mulch. Wet grass sticks together and can leave uneven patches.
How often should I sharpen the blade?
North Dakota State University Extension says to sharpen or replace the blade about once a year, depending on how much you mow. Check the blade before each season, and again if you notice torn grass tips.
Can a push mower handle a very overgrown lawn in one pass?
Not if you follow the one-third rule. Plan for more than one mowing, set the deck high first, and lower it in steps. The YHUBHSIS listing says the mower cuts grass up to 7.5 inches tall, but its highest setting is 1.8 inches, so one pass at that height would remove far more than a third.
Bottom line
To mow tall grass with a push mower, follow one rule: never remove more than one-third of the blade in one mowing. Set the deck high, mow dry grass, keep the blade sharp, and lower the height in steps over several passes until the lawn is in the 2.5 to 3.5 inch range that both extension sources recommend. Check the height settings in the listing before you buy, because a mower with a low top setting cannot do the first cut on very tall grass.
Related reading: Best Lawn Mowers for Mowing Tall Grass: Cutting Height Compared and How to Mow a Slope With an Electric Mower.
Products
YHUBHSIS 14-Inch Push Reel Lawn Mower with Grass Catcher. The listing describes five blades, 8-inch polymer wheels, a height range of 0.6 to 1.8 inches, and a grass catcher that may not catch every clipping.
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Walensee 16-Inch 5-Blade Push Reel Lawn Mower. The listing gives a 16-inch cutting width, 8.5-inch drive wheels, four height settings from 0.6 to 1.5 inches, and a removable 7.9-gallon grass catcher. Its bullets advise trimming taller grass in stages.
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Sun Joe MJ502M Manual Push Reel Lawn Mower, 20-Inch. The listing describes a 20-inch cutting path, five steel blades, nine height positions up to 2.44 inches, and an 8.5-gallon grass catcher.
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Hoteche 10-Amp Corded Electric Lawn Mower. The bullets describe a 12.6-inch cutting deck, three height settings from 1 to 2.2 inches, and a 30L grass bag. The listing says it is a corded electric mower with a 1200W brush motor.
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DORTALA Corded 14-Inch Electric Push Mower. The listing gives three height settings at 1, 1.8 and 2.5 inches, a 9.3-gallon collection box that can be detached for mulching, and a folding handle for storage.
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CRAFTSMAN V20 20-Inch Push Mower. The listing describes a battery push mower with a dual-lever height adjustment from 1.5 to 3.5 inches, a collection bag, and two 5.0Ah batteries and two chargers listed as included.
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