How to Mow Tall Grass With a Push Mower Safely
As an Amazon Associate we earn from qualifying purchases.
How to cut tall grass with a push mower safely comes down to three habits: raise the deck first, mow in stages, and never take more than one-third of the leaf height in a single pass. Iowa State University Extension advises that no more than one-third of the total leaf area should come off in one mowing. Work at a steady walking pace, keep the deck clear of wet clumps, and check the blade before you start. Take the grass down over two or three sessions and you protect the lawn while the mower does less work each time.
Quick answer
- Set the deck high for the first pass. Lower it only after the grass is back near its normal height.
- Follow the one-third rule: remove no more than one-third of the leaf height per mowing.
- Mow in two or three sessions if the grass is far over its target height.
- Check that the blade is sharp, the deck is clean and the safety controls work before you begin.
Why tall grass needs a different approach
Iowa State University Extension states that “shorter mowing heights require more frequent mowing, not less.” The same page advises mowing “as often as needed so that no more than one-third of the total leaf area is removed in a single mowing.” Removing more than that weakens the grass and makes it more prone to drought stress, disease and weeds. A lawn that has grown tall over a week or two is exactly the case where a single low cut does the most damage, because the mower removes a large share of the leaf at once.
The practical result is simple. Cut high first, let the grass recover for a few days, then drop the deck one notch and mow again. The mower does less work per pass, the clippings are shorter and the lawn looks better sooner.
Step 1: Check the mower before you start
A push mower is only as good as its blade. A dull blade tears the tops of tall grass, which turns the tips brown and leaves the lawn ragged for days. Before you start, inspect the blade for nicks and bends, and make sure it is tight on its bolt. If the blade is loose or damaged, replace it rather than mowing with it.
Clear the deck of old clippings and mud. Wet, packed grass sticks under the deck, and a dirty deck makes the mower harder to push. Empty the grass catcher if you use one, since a full bag restricts airflow and can leave clumps on the lawn.
If your mower has a safety bail or switch, confirm it engages properly. Read the owner’s manual for your model, because the manual is the authority on how the controls work. The listings used here do not describe the start procedure in detail, so do not assume a control works the same way on a different mower.
Step 2: Set the cutting height
Most push mowers have a height lever or a set of positions. Start at the highest setting. The listing for the Hoteche 10-amp corded mower describes three height adjustments from 1 inch to 2.2 inches, and says the 2.2-inch setting is for taller grass. The Walensee 16-inch reel mower lists four cutting heights from 0.6 to 1.5 inches. The DORTALA 14-inch electric mower lists three positions: 1 inch, 1.8 inches and 2.5 inches.
The difference between these ranges matters when grass is tall. A mower whose lowest setting is 1 inch can still take a high first cut if its top setting is 2.5 inches. Use the top setting for the first session, even if your target height is much lower.
Step 3: Mow in stages
Here is a sensible sequence for a lawn that has grown well past its target height:
- First session: Mow at the highest setting. Aim to take off only about a third of the leaf height.
- Wait: Give the grass a few days to recover, depending on weather and growth.
- Second session: Drop the deck one position and mow again.
- Final session: Lower to your normal height once the lawn is back in its usual range.
If the grass is very tall, you may need three or more sessions. That is normal. The goal is a healthy lawn, not a fast finish. Dropping the deck to the lowest setting right away usually leaves brown tips and bare patches.
Step 4: Walk at a steady pace and overlap passes
A push mower works best at a steady walking pace. Pushing too fast leaves uncut strips, and pushing too slowly can bunch clippings under the deck. Overlap each pass by a few inches so that no strip is missed. The Walensee listing describes a 16-inch cutting width and the DORTALA listing describes a 14-inch deck, so the overlap should be a few inches from the edge of the previous row on either machine.
Mow in a pattern rather than back and forth along the same line. Changing direction each session keeps the grass from being pressed flat in one direction, which helps it stand up after the cut.
Step 5: Deal with clippings
Tall grass produces a lot of clippings. Leaving a thick layer on the lawn can smother the grass beneath it, so either bag the clippings or rake them out after the cut. Mulching works well when the layer is thin. The Hoteche listing describes a 30-liter grass bag with a quick-release design. The DORTALA listing describes a 35-liter, 9.3-gallon collection box that can be detached for mulching. The listings do not state how much clipping volume either container holds after tall grass is packed down.
Safety basics
Wear closed shoes, long trousers and eye protection. Clear the lawn of stones, sticks and toys before you start, since a push mower can throw debris. Keep hands and feet away from the blade, and never reach under the deck while the motor or engine is running. Turn off the mower and wait for the blade to stop before you tip it, clear a clog or check the blade. For an electric mower, unplug it as the manual directs. For a gas mower, disconnect the spark plug wire before any blade work.
Keep the cord clear of the blade path on a corded mower, and do not mow in wet conditions with any electric model. For a health concern, or if the job involves heat, heavy grass or long sessions, take breaks and drink water. Ask your doctor before starting a demanding job if you have a condition that limits your activity.
Mistakes to avoid
- Cutting the whole height in one pass. This removes too much leaf area and stresses the grass.
- Mowing wet grass. Wet clippings clump and the cut is uneven.
- Running a dull blade. Torn tips turn brown and the lawn looks ragged.
- Skipping the deck clean. Packed clippings reduce airflow and make the mower harder to push.
- Dropping to the lowest setting too early. Scalping exposes soil and weakens the grass.
Mowers from the listing data
You do not need a specific mower to follow these steps. The three listings below show the cutting height and collection facts that matter for tall grass. Each link goes to the listing on Amazon.
Hoteche 10-amp corded electric mower
The listing describes a 12.6-inch cutting width, three height adjustments from 1 to 2.2 inches and a 30-liter grass bag. It is a corded electric model, and the listing gives a weight of 16 pounds. The listing says the 2.2-inch setting is for taller grass. The listing does not state a cord length, so measure your outdoor run before you mow.
Walensee 16-inch reel mower
The listing describes a manual reel mower with five blades, a 16-inch cutting width, 8.5-inch drive wheels and four cutting height settings from 0.6 to 1.5 inches. It has a removable 7.9-gallon grass catcher. The listing says it needs no gas, electricity or batteries. A reel mower cuts with scissor-like action, so the listing’s height range suggests it suits a lawn kept at a fairly even height. The listing does not state how it handles very tall or matted grass, so start at the top setting and expect more passes.
DORTALA 14-inch corded electric push mower
The listing describes a 12-amp, 1500-watt motor, a 14-inch cutting deck and three cutting heights at 1, 1.8 and 2.5 inches. It includes a 9.3-gallon collection box that can be attached for side discharge or removed for mulching. The listing describes a double-switch safety lever that returns to the off position when released. The listing does not state the cord length.
FAQ
How high should I set the deck for very tall grass?
Start at the highest setting your mower offers. The rule is to remove no more than one-third of the leaf height in one session. If the grass is much taller than that, plan on two or three sessions and lower the deck one step at a time between them.
Why not cut the grass short in one go to save time?
Cutting too much at once stresses the plant and can leave brown tips or bare patches. Iowa State University Extension notes that shorter mowing heights need more frequent mowing, so a single low cut often costs more time later as the lawn recovers.
Should I bag the clippings after cutting tall grass?
Bag them or rake them out if the layer is thick. A thin layer can be left to mulch, but heavy clippings can smother the grass beneath. Choose a bag or mulching setup that suits your mower.
Is a reel mower a good choice for tall grass?
A reel mower works best on lawns that are kept at a fairly even height. The Walensee listing gives a top cutting height of 1.5 inches, which means a very tall lawn will need several passes from the highest setting. For a very tall lawn, a powered push mower with a high first setting is often more practical.
Can I cut tall grass if the mower is dull?
You can, but you should sharpen or replace the blade first. A dull blade tears the grass and leaves ragged tips. Check the blade bolt for tightness after any blade work.
Where can I read more on lawn care?
Extension pages are a good reference. The Iowa State University Extension FAQ on mowing frequency and cutting height is the source for the one-third rule used in this article.
Bottom line
Cut high first, remove no more than one-third of the leaf height in each session, and bring the grass down to your normal height over two or three mowings. A clean blade, a clear deck and a steady walking pace do most of the rest.
Related reading
For a wider look at choosing a mower for tall grass, see Best Lawn Mowers for Mowing Tall Grass: Cutting Height Compared. If you also trim the edges after a tall-grass cut, How to Cut Tall Weeds With a String Trimmer covers that job.
