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I mow about weekly from April 15th to October 15th, that's around 28 times preseason. Each mowing takes 1 1/2 hours (front and back), so I mow around 42 hours per year. I sharpen the blades at the start of the season and at mid-season or so, meaning I sharpen the blades every 21 hours, give or take.

I'd like to hear how that compares to others. I've heard that some businesses sharpen blades daily, which seems extreme. I've tried checking the blade but it never really looks sharp to me. Feedback, please. Is every 21 hours soon, late or average?

It depends on what you're mowing.

Thick bluegrass will require a sharper blade than thin Tall Fescue. Other types, such as Zoysia, are probably harder on blades than bluegrass.

I have the thin Tall Fescue and once a year is all I do. I'm lazy. Don't be like me.

It certainly can't hurt anything but your budget by sharpening more frequently.

I do them once a year. To me a lot of sharping just puts a lot of unnecessary wear on them.

I agree with the statement that it depends on what your mowing, plus what results your after. I have seen a number of tests using sharp blades and dull blades, dull blades definitely tend to tear the grass blades which during warm weather leave the lawn with a off green/whitish look. I purposely did a test of my own after mowing a few acres on my acreage which was taller brome grass that usually takes its toll on my blades. I didn't do the usual sharpening afterwards and went out and mowed half of my front yard (Kentucky Bluegrass) then went and sharpened my blades and finished the front yard, well it was noticeable from the time I finished also for the rest of the week. In my case it looked off color with the dull blades throughout the mowing cycle.

My opinion is run your own test to see if it is a big enough difference to justify the additional sharpening, in the end the best way to determine your personal sharpening intervals is watch the quality of cut and reach under and feel the cutting edge. With time you will get a feel for where you want to keep the sharpness of the blades.

Freshly sharpened blades noticeably reduce stress on the engine and keeps the grass looking greener and neater IMHO. I like to sharpen about once a month (four 1.5 - 2 hour mows), but I get lazy about it. The lift fins on my blades seem to wear out long before I run out of blade to sharpen...

I used to sharpen blades about every 4th mow but I'm older now and getting down on the ground is hard. Getting up is a lot harder.
My old mower made so many trips to the shop I'd tell them to put on new blades or ask them to sharpen them instead of me sharpening.

But now I have a new mower and we're in the honeymoon stage. (I have actually spayed it off after mowing each time.) So maybe I'll give a little more care to the blades.
I'll probably sharpen two or three times each season.

To be honest, my country yard is field grass. It's not a "lawn" and I have not been able to actually see a big difference after sharpening. I imagine it looks better....
And that nice sharp edge just doesn't stay that way very long.

Glad to hear other people don't sharpen every time.

I agree with all the points above. It's harder to get back up than get on the ground. The engine definitely likes a sharp, balanced blade. The latter is just as important, maybe more. A push or walk behind mower needs to keep the RPM up to a certain level to get the optimum cut in thick, lush grass. A dull, imbalanced blade means less available horse power going where it needs to go and instead rattles yer fillings and causes deck cracks, loosens fasteners, excessive wear on crank seals etc. Lower vibration levels means longer service life for your equipment.

The shredding of the grass blades with a dull blade noted above isn't only a cosmetic defect, it also allows for the introduction of turf diseases through the "wound", a sharp cut slices more cleanly and heals quickly. This is one reason reel type mowers produce a superior finish, they have a scissors action, instead of a rotary bash.

Even new blades need sharpening too, sounds nuts but it's true. Balance can be off quite a bit too. On the other hand a razor sharp blade isn't optimal either. One thing you can do, is go over a previously sharpened blade with just a few strokes of a draw file after every other mow say, if you keep up on it.

TonyPrin said:

I mow about weekly from April 15th to October 15th, that's around 28 times preseason. Each mowing takes 1 1/2 hours (front and back), so I mow around 42 hours per year. I sharpen the blades at the start of the season and at mid-season or so, meaning I sharpen the blades every 21 hours, give or take.

I'd like to hear how that compares to others. I've heard that some businesses sharpen blades daily, which seems extreme. I've tried checking the blade but it never really looks sharp to me. Feedback, please. Is every 21 hours soon, late or average?

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With a Honda walk behind mower I never sharpen the blades, just replace them. With a commercial ride on with mulching deck, the blades are sharpened very regularly, probably every 8 or so hours of operation. The blades can wear very quickly with a mulching deck, and the "fins" always wear out well before the cutting edge, although the cutting edge does form an arc near the edges. I always balance with a dedicated balancer (Tecomec).

My question is how many sticks do you hit when mowing? I have tons of trees around my property and pine trees seem to be the worst. It's almost impossible to pick everyone of them up. I typically just pick the large ones up and mow over the smaller ones.

I went about 5 years before I sharpened the blades on mine. I can't tell you the number of hours I mow each season but I typically mow every 2 weeks (I have zozyia grass) from late May to early October about 3 hours each time I mow.

The main reason I sharpened them then was the bracket on the deck broke and I had to remove the deck to weld the bracket back on. Probably from trying to squeeze a lawnmower with a 46" deck through a 48" opening in my yard barn!

I installed new blades last year after I ran over a Shepard's hook my daughter threw out in the yard and bent the blades.

Once again I sharpened the second set of blades this spring after I spindle broke last fall.

To be honest, I can't really tell much of a difference after I did sharpen the blades!

Which begs the question. When you sharpen a blade on a bench grinder, do you guys just put an edge on one side or sharpen it to a point like a knife?

I probably average 60 per year on my mower.
Blades get sharpened once a year at the end of the season.

turbofiat124 said:

I typically just pick the large ones up and mow over the smaller ones.

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I do that too.

turbofiat124 said:

Which begs the question. When you sharpen a blade on a bench grinder, do you guys just put an edge on one side or sharpen it to a point like a knife?

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Only sharpen the bevel side, like a wood chisel. Maintain the bevel angle, should be about 45 degrees, I just eyeball it. Don't bring the edge down to a real fine point, you don't need to shave hair with it. You should be able to see a hairline flat edge when you look at the cutting edge straight on. I've seen 1/64" recommended, but I've never measured it. Don't over heat the edge on the grinder. If you see any blueing you just lost the temper, and it will dull quicker. Also a bench grinder will create a hollow grind which won't be as strong as a flat grind. I like to clamp the blades in my workmate or to a bench and use an angle grinder.

I like a nice big file.

I just got a new blade and it does not appear to be sharp at all. You know, won't cut warm butter. Is it customary to have to sharpen a new blade before first use?

pgrimes@insight.rr.com said:

I just got a new blade and it does not appear to be sharp at all. You know, won't cut warm butter. Is it customary to have to sharpen a new blade before first use?

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Mower blades needn't be very sharp. Keep in mind, you're cutting grass not steak. The best way to see if the blade is sharp may be to try it and examine the grass afterward. If the blade cuts the grass rather than tearing it, you're fine.

pgrimes@insight.rr.com said:

I just got a new blade and it does not appear to be sharp at all. You know, won't cut warm butter. Is it customary to have to sharpen a new blade before first use?

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As the blades are supplied is as they should be used.
A finer edge will cut better but will wear fasted and dent much more easily, so it is a trade off.
The actual sharpness that works best will depend upon what type of grass you mow and what type of soil you have.